|English name||Aluminum alloy|
|Melting point||660 ° C|
- 1 Aluminum alloy
- 2 History development
- 3 Physical and chemical properties
- 4 Manufacturing process
- 5 Detection method
- 6 Material classification
- 7 Construction method
- 8 Application field
- 9 Main products
- 10 Performance requirements
- 11 Discussions
- 12 What Links Here
- 13 References
- Aluminum alloy (non-ferrous metal structural material).
- Aluminum alloy is one of the most widely used non-ferrous metal structural materials in the industry and has been widely used in aviation, aerospace, automotive, machinery manufacturing, marine and chemical industries. With the rapid development of the industrial economy, the demand for aluminum alloy welded structural parts is increasing, and the research on the weldability of aluminum alloys is also deepened. Aluminum alloys are currently the most widely used alloys.
- Alumina was reduced to aluminum by electrolysis in the laboratory in 1808. It was used as a building material in the United States on the spire of the Washington Monument in 1884. Aluminum alloys with various metal elements have been widely used in the construction industry. In all aspects.
- In 1908, Alcoa invented the electrician aluminum alloy 1050, and made it into a steel core aluminum stranded wire, creating a pioneer in high-voltage remote transmission.
- In 1915, Alcoa invented the 2017 alloy and invented the 2024 alloy in 1933, which enabled the rapid expansion of aluminum in aircraft applications. In 1933, Alcoa invented the 6061 alloy, which immediately created an extruder quenching process that significantly expanded the range of extrusion profiles.
- In 1943, Alcoa invented the 6063 alloy and the 7075 alloy, creating a new era of high-strength aluminum alloy.
- In 1965, Alcoa invented the A356 cast aluminum alloy, which is a classic cast aluminum alloy.
- With the deep research on aluminum alloy materials, high-strength aluminum alloys (2000, 7000 series) have achieved more than 80% of their structural quality with their excellent comprehensive performance on commercial aircraft, so they have been recognized by the global aviation industry. Generally attached. Aluminum alloys began to be applied to life, military, and technology. 
Physical and chemical properties
- The aluminum alloy has low density, but high strength, close to or exceeds high-quality steel, good plasticity, can be processed into various profiles, has excellent electrical conductivity, thermal conductivity and corrosion resistance. It is widely used in industry and is used second only to steel. Some aluminum alloys can be heat treated to achieve good mechanical properties, physical properties and corrosion resistance. Hard aluminum alloy belongs to AI-Cu-Mg system, generally contains a small amount of Mn, which can be heat treated and strengthened. It is characterized by high hardness but poor plasticity. Super-hard aluminum is a Cu-Mg-Zn system, which can be heat-treated and strengthened. It is the highest strength aluminum alloy at room temperature, but has poor corrosion resistance and high temperature softening. The wrought aluminum alloy is mainly an Al-Zn-Mg-Si alloy. Although it has many kinds of elements, it has a small content, so it has excellent thermoplasticity and is suitable for forging, so it is also called forged aluminum alloy. 
- The density of pure aluminum is small (ρ=2.7g/cm 3 ), about 1/3 of iron, low melting point (660°C), aluminum is face-centered cubic structure, so it has high plasticity (δ: 32~40%), ψ: 70~90%), easy to process, can be made into various profiles, plates, good corrosion resistance. However, the strength of pure aluminum is very low, and the annealing state σb value is about 8 kgf/mm 2, so it is not suitable as a structural material. Through long-term production practices and scientific experiments, people gradually strengthened aluminum by adding alloying elements and applying heat treatment, which resulted in a series of aluminum alloys. The alloy formed by adding certain elements can have higher strength while maintaining the advantages of pure aluminum, and the σb value can reach 24 to 60 kgf/mm 2, respectively. This makes its "specific strength" (the ratio of strength to specific gravity σb / ρ) outperforms many alloy steels and becomes an ideal structural material, widely used in machinery manufacturing, transportation machinery, power machinery and aviation industry, aircraft fuselage, skins, compressors, etc. are often made of aluminum alloy to reduce their own weight. The use of aluminum alloy instead of steel plate welding can reduce the structural weight by more than 50%.
|Typical Mechanical Properties Of Aluminum Alloys (Typical Mechanical Properties)|
|Aluminum alloy grade
|Tensile strength (25 ° C MPa)||Yield strength (25°C MPa)||Hardness 500kg force 10mm ball||Elongation 1.6mm (1/16in) thickness|
|Typical Physical Properties Of Aluminum Alloys (Typical Physical Properties)|
|Aluminum alloy grade and status||Thermal expansion coefficient
(20-100 ° C)
|Melting point range
|Conductivity 20 ° C (68 ° F)
|Resistivity 20 ° C (68 ° F)
|Density (20 ° C) (g / cm3)|
|Chemical Composition Limit Of Aluminum|
|Silicon Si||Iron Fe||Copper Cu||Manganese Mn||Magnesium Mg||Chromium Cr||Zinc Zn||Titanium Ti||Other||Aluminum|
- Aluminum and aluminum alloys can be smelted in a variety of different ways. Commonly used are coreless induction furnaces and trough induction furnaces, crucible furnaces and reflective open hearth furnaces (using natural gas or fuel oil combustion) as well as electric resistance furnaces and electric radiation furnaces. Furnace materials range from high-quality pre-alloyed ingots to furnaces made up of low-grade waste. However, even under the most suitable conditions for smelting and casting, molten aluminum is susceptible to three types of adverse effects:
- • Under high temperature conditions, the adsorption of hydrogen causes an increase in hydrogen dissolved in the melt over time.
- • At high temperatures, the melt oxidizes over time.
- · Loss of alloying elements.
- Hydrogen is easily adsorbed by molten aluminum. Unfortunately, in molten aluminum alloys, the solubility of hydrogen is substantially greater than its solubility in solid aluminum. When the aluminum alloy solidifies, hydrogen gas is discharged from the melt, and the shrinkage porosity is enlarged and amplified, accompanied by loss of mechanical properties. Hydrogen is generally derived from wet charge and wet melting tools, but the primary source of hydrogen is moisture in the environment. Since it is almost impossible to prevent the adsorption of hydrogen gas during smelting, hydrogen must be removed from the melt before pouring. The most commonly used method is to blow dry nitrogen or argon bubbles into the melt. The use of chlorine to remove hydrogen is particularly effective. However, it is often excluded from production for environmental and safety reasons.
- In the past, the amount of hydrogen dissolved in the melt has been measured by a reduced pressure test by injecting a sample of molten aluminum into a steel cup and allowing it to solidify in a vacuum chamber. Observing the solidification process, it was found that the degree of bubble change during solidification indicates the amount of hydrogen present. At the same time, the size of the bubble formed can be checked by using the sliced sample after solidification. Unfortunately, these methods are not precise and are greatly affected by the presence of oxide particles in the melt as nucleation of hydrogen bubbles. A better way to test dissolved hydrogen is to use a specially designed instrument that uses liquid extraction techniques to display hydrogen.
- Aluminum instantaneously forms a very stable oxide on the surface of the melt. The rate of oxidation increases with increasing temperature and the presence of certain alloying elements such as magnesium and barium. However, if the surface of the aluminum melt is not disturbed, the oxide film formed on the surface is self-limiting, and any turbulent flow will stir the oxide film into most of the melt and produce a fresh surface to facilitate More oxide formation. The resulting oxide film and oxide impurities are very detrimental to the properties of the cast aluminum part, however, turbulence is caused during alloy smelting, transfer of molten metal or casting and casting.
- The oxide particles in the melt become cores that form craters and pores. In the absence of oxide impurities, the pores and micropores are substantially eliminated. For the production of cast aluminum parts, reducing oxide impurities is a particularly important condition. Since they usually have a very large difference between the liquidus and the solidus, and condense in a porous state, it is difficult to supply the pores.
- The oxide film of the casting forms a fragile surface that is extremely vulnerable to failure. The non-uniformity of the mechanical properties of the cast aluminum alloy is precisely caused by the existence of these oxide films. Without these oxide films, the unevenness will be reduced and the casting properties will be reduced. The repeatability is better than that of forgings. When X-rays are used, these oxide films are usually invisible, but they must be prevented beforehand and not repaired afterwards.
- In the molten state, the coverage of the flux can be utilized to control the oxide. These fluxes are typically magnesium chloride salts. They float on the surface of the melt. However, it is still necessary to periodically remove oxides from the surface of the melt, and the molten oxide impurities can be removed from the melting furnace by passing the melt through the filter bed. For smaller scale production, filters can be placed in the gating system to remove oxides.
- In order to prevent the formation of an oxide film in the casting, it is necessary to let the metal enter the cavity of the mold in a state of turbulent flow. For most castings, this is not possible with gravity casting because the head height of the sprue speeds up the flow and causes turbulence, so anti-gravity or liquid level casting techniques must be used. This filter slows the flow of metal, making it slow enough to prevent oxide formation. In addition, the cavity of the mold must be injected from the bottom, and the order of the injection of each liquid level of the casting must be carefully designed to avoid the occurrence of a “waterfall”—the liquid metal in the mold drops from a higher liquid level to a lower liquid level. An oxide is formed on the surface of the nascent metal. By injecting the mold from the bottom, the oxide layer on top of the liquid metal will rise to the top of the upper flask level and into the top of the riser so that the casting is not damaged.
- Many cast aluminum alloys contain elements such as magnesium that slowly react with oxygen. The molten metal is stored for too long, and these elements are gradually oxidized, resulting in chemical composition of the casting that is not up to standard, while other alloying elements, For example, zinc with a low gasification pressure will also evaporate from the surface of the bath. 
- Silicon has a corrosive effect on cemented carbide. Although aluminum alloys exceeding 12% Si are generally referred to as high-silicon aluminum alloys, diamond tools are recommended, but this is not absolute, and the increasing silicon content increases the destructive power of the tools. Therefore, some manufacturers recommend the use of diamond tools when the silicon content exceeds 8%.
- An aluminum alloy with a silicon content of between 8% and 12% is a transition zone, either a normal hard alloy or a diamond tool. However, the use of cemented carbide should use a PVD (physical coating) method, without aluminum, a tool with a small film thickness. Because the PVD method and small film thickness make it possible for the tool to maintain a sharper cutting edge (otherwise, to avoid abnormal growth of the film at the cutting edge, it is necessary to passivate the cutting edge sufficiently, the cutting aluminum alloy will not be sharp enough) The aluminum material of the film material may cause the blade film layer to interact with the workpiece material to break the bond between the film layer and the tool substrate. Because the super-hard coating is mostly a compound of aluminum, nitrogen and titanium, it may cause chipping due to a small amount of peeling off of the cemented carbide substrate as the film peels off.
- It is recommended to use one of the following three types of tools:
- 1. Uncoated ultra-fine particle cemented carbide tool
- 2. Carbide tools with no aluminum plating (PVD) method, such as TiN, TiC, etc.
- 3. Using diamond cutters
- The chip space of the tool should be large. It is generally recommended to use 2 teeth, and the front and back angles should be large (such as 12°-14°, including the end tooth back angle).
- If it is just a general milling surface, it can be used with a 45° lead angle indexable face milling cutter, and a blade specially designed for machining aluminum alloy should be better.
- Common aluminum plate thickness: high-grade metal roofing (and curtain wall) system is generally 0.8-1.2mm (compared to the traditional general ≥ 2.5mm).
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- Pure aluminum smelting and pressure processing products
- The deformed aluminum alloy can withstand pressure processing. It can be processed into aluminum alloy materials of various shapes and specifications. Mainly used in the manufacture of aviation equipment, building doors and windows. The deformed aluminum alloy is further divided into a non-heat treatable reinforced aluminum alloy and a heat treatable reinforced aluminum alloy. The non-heat-treated reinforced type cannot be improved by heat treatment to improve mechanical properties, and can only be strengthened by cold working deformation. It mainly includes high-purity aluminum, industrial high-purity aluminum, industrial pure aluminum, and rust-proof aluminum. The heat-treatable reinforced aluminum alloy can be improved in mechanical properties by heat treatment such as quenching and aging, and can be classified into hard aluminum, wrought aluminum, super-hard aluminum, and special aluminum alloy.
- Cast aluminum alloy can be divided into aluminum silicon alloy, aluminum copper alloy, aluminum magnesium alloy, aluminum zinc alloy and aluminum rare earth alloy according to chemical composition, among which aluminum silicon alloy has hypereutectic silicon aluminum alloy and eutectic silicon aluminum alloy. Crystalline silicon aluminum alloy, cast aluminum alloy used in the as-cast state.
Deformed aluminum alloy
- One series: 1000 series aluminum alloys represent 1050, 1060, 1100 series. The 1000 series is the most aluminum-containing series in all series. The purity can reach above 99.00%. Because it does not contain other technical elements, the production process is relatively simple and the price is relatively cheap. It is the most commonly used series in the conventional industry. Most of the circulation in the market is the 1050 and 1060 series. The 1000 series aluminum plates are based on the last two Arabic numerals to determine the minimum aluminum content of the series. For example, the last two Arabic numerals of the 1050 series are 50. According to the international brand nomenclature, the aluminum content must reach 99.5% to be qualified products. China's aluminum alloy technical standards (gB/T3880-2006) also clearly stipulates that the aluminum content of 1050 reaches 99.5%. The same reason, the aluminum content of the 1060 series aluminum plate must reach 99.6% or more.
- Second series: 2000 series aluminum alloy stands for 2024, 2A16 (LY16), 2A02 (LY6). The 2000 series aluminum plates are characterized by high hardness, with the highest content of copper, about 3-5%. The 2000 series of aluminum rods are aerospace aluminum and are not commonly used in conventional industries.
- Three series: 3000 series aluminum alloy is mainly composed of 3003 and 3A21. China's 3000 series aluminum sheet production process is relatively good. The 3000 series aluminum rods are mainly composed of manganese. The content is between 1.0 and 1.5, which is a series with better anti-rust function.
- Four series: 4000 series aluminum rods represent 4A01 4000 series aluminum sheets belong to the series with higher silicon content. Typically the silicon content is between 4.5 and 6.0%. It is a building material, mechanical parts forging materials, welding materials; low melting point, good corrosion resistance, product description: heat-resistant, wear-resistant characteristics
- Five series: 5000 series aluminum alloy represents 5052, 5005, 5083, 5A05 series. 5000 series aluminum rods belong to the more common alloy aluminum plate series. The main element is magnesium, and the magnesium content is between 3-5%. Also known as aluminum-magnesium alloy. The main features are low density, high tensile strength, high elongation and good fatigue strength, but they cannot be heat treated. The weight of aluminum-magnesium alloy is lower than other series under the same area. It is also widely used in conventional industries. In China, 5000 series aluminum plates belong to one of the more mature aluminum plate series.
- Six series: 6000 series aluminum alloy represents 6061 mainly contains magnesium and silicon two elements, so the advantages of 4000 series and 5000 series are concentrated. 6061 is a cold-processed aluminum forged product, which is suitable for applications with high corrosive and oxidizing requirements. Good workability, easy coating and good processability.
- Seven series: 7000 series aluminum alloy represents 7075 mainly contains zinc. Also belonging to the aviation series, it is an aluminum-magnesium-zinc-copper alloy, a heat-treatable alloy, a super-hard aluminum alloy, has good wear resistance, and also has good weldability, but has poor corrosion resistance.
- Eight series: 8000 series aluminum alloy is more commonly used for 8011. It belongs to other series. Most of the applications are aluminum foil. It is not very common for producing aluminum rods.
- Nine series: 9000 series aluminum alloy is a spare alloy.
- Aluminum alloy material category
- Aluminum alloy pure aluminum products
- There are two types of pure aluminum smelting products and pressure processed products. The former is represented by chemical composition Al, and the latter is represented by Chinese Pinyin LV (aluminum, industrial).
- Pressure processing aluminum alloy
- Cast aluminum alloy
- The cast aluminum alloy (ZL) is classified into four types according to the main elements other than aluminum in the composition, such as silicon, copper, magnesium and zinc, and the code numbers are 100, 200, 300, and 400, respectively.
High strength aluminum alloy
- High-strength aluminum alloy refers to aluminum alloy with tensile strength greater than 480 MPa, mainly for rust-proof aluminum alloy, hard aluminum alloy, super-hard aluminum alloy, wrought aluminum alloy, aluminum-lithium alloy in pressure-processed aluminum alloy.
- Deformed aluminum and aluminum alloy status, code
- 1 Scope
- This standard specifies the status code of the deformed aluminum alloy.
- This standard applies to aluminum and aluminum processed products.
- 2. Basic principles
- 2.1 The basic status code is represented by an English capital letter.
- 2.2 The subdivision status code is represented by a base status code followed by one or more Arabic digits.
- 2.3 basic status code
- Basic status is divided into 5 kinds
- Code name description and application
- F Free-machining conditions are applicable to products that have no special requirements for work hardening and heat treatment conditions during the molding process. The mechanical properties of the product are not specified.
- The O annealed state is suitable for processed products that have been fully annealed to obtain the lowest strength.
- H The work hardening state is suitable for products that are strengthened by work hardening, and the product may be subjected to additional heat treatment after the work hardening may or may not be reduced in strength.
- W Fused heat treatment state ( an unstable state ), only applicable to alloys that are naturally aged at room temperature after solution heat treatment. This state code only indicates that the product is in the natural aging stage.
- T Heat treatment state (different from F, O, H state) Applicable to products that have been stabilized after (or without) work hardening after heat treatment. The T code must be followed by one or more Arabic digits. The first digit after the T word indicates the basic type of heat treatment (from 1 to 10), after which the digits indicate changes in the details of the heat treatment. Such as 6061-T 62; 5083-H 343 and so on.
- T1—cools from the molding temperature and is naturally aged to a substantially stable state.
- T2—annealed state (used only for castings).
- T3—naturally aged after solution treatment.
- T31—Solid solution is naturally aged after cold work (1%).
- T36—Solid solution is naturally aged after cold work (6%).
- T37 - solution treatment cold work (7%) after natural aging, for 2219 alloy.
- T4—naturally aged after solution treatment.
- T41—Boiling water quenching after solution treatment.
- T411—Solid-cooling to room temperature after solution treatment, hardness between O and T6, and low residual stress.
- T42—naturally aged after solution treatment. Processed by the user, suitable for 2024 alloy, the strength is slightly lower than T4.
- T5—Manual aging after cooling from the molding temperature.
- T6—Artificial aging after solution treatment.
- T61-T41+ artificial aging.
- T611 - solution treatment, boiling water quenching.
- T62—Artificial aging after solution treatment.
- T7 - Stabilized after solution treatment. Improve dimensional stability, reduce residual stress, and improve corrosion resistance.
- T72—Over-aging after solution treatment.
- T73—Grade aging after solution treatment, the strength is lower than T6, and the corrosion resistance is remarkably improved.
- T76—Grade aging after solution treatment.
- T8—Solid solution treatment is artificially aged after cold work.
- T81—Cold work after solution treatment, artificial aging. In order to improve the deformation after solution treatment and improve the strength.
- T86 - cold work after solution treatment (6%), artificial aging.
- T87-T37+ artificial aging.
- T9 - after artificial solution treatment, artificial aging and then cold work.
- T10—cools from the molding temperature and is cold after artificial aging.
- Tx51—Stretching to eliminate residual stress after solution treatment.
- The permanent deformation of the plate is 0.5~3%, and the permanent deformation of the bar and profile is 1~3%.
- X stands for 3, 4, 6 or 8, such as T351, T451, T651, T851, which is suitable for plates, drawn rods, wires, and is aged after stress relief without any correction. T3510, T4510, T8510, suitable for extruded profiles, after the tension is relieved of stress, the flatness is corrected to meet the tolerance and is time-sensitive.
- Tx52—Compressive deformation to eliminate residual stress after solution treatment, 2.5% plastic deformation after solution treatment and then aging, such as T352 and T652.
- Tx53—Remove thermal stress.
- Tx54—Compressive deformation to eliminate residual stress after solution treatment of precision forgings.
- Repair is an important part of the aluminum alloy die forging process. Because aluminum alloy is soft at high temperature, it has high viscosity and poor fluidity, it is easy to stick mold and produce various surface defects (folding, burrs, cracks, etc.). Before the next process, it must be polished and repaired to remove surface defects. Clean, otherwise the defects will be further expanded in the subsequent process, and even cause the forgings to be scrapped.
- Tools for repairing include pneumatic grinders, pneumatic milling cutters, electric milling cutters and flat shovel. Before the repair, the defect is firstly found through corrosion. The repaired part should be smoothly transitioned, and its width should be 5 to 10 times of the depth.
- Aluminum alloy pressure processing products are divided into seven categories: rustproof (LF), hard (LY), forged (LD), superhard (LC), coated (LB), special (LT) and brazed (LQ). The state of the commonly used aluminum alloy material is three types of annealing (M igniter), hardening (Y), and hot rolling (R).
- Die casting characteristics
- Die casting is abbreviated as die casting, which is a casting method in which a molten alloy liquid is poured into a pressure chamber, a cavity of a steel mold is filled at a high speed, and the alloy liquid is solidified under pressure to form a casting. The main features of die casting that distinguish it from other casting methods are high pressure and high speed.
- (1) The molten metal fills the cavity under pressure and crystallizes and solidifies at a higher pressure. The common pressure is 15-100 MPa.
- (2) The molten metal fills the cavity at a high speed, usually at 10-50 m/s, and some may exceed 80 m/s (the line speed of the cavity introduced into the cavity through the gate) - the metal gate speed, so the metal The filling time of the liquid is extremely short, and the cavity can be filled in about 0.01 to 0.2 seconds (depending on the size of the casting). Die-casting machines, die-casting alloys and die-casting molds are the three major elements of die-casting production and are indispensable. The so-called die-casting process is to organically combine these three elements to enable the stable, rhythmic and efficient production of qualified castings, even high-quality castings, with the appearance, good internal quality, dimensional conforming to drawings or agreements.
- Die casting fluidity
- Fluidity refers to the ability of an alloy liquid to fill a mold. The amount of fluidity determines whether the alloy can cast complex castings. The eutectic alloy has the best fluidity in the aluminum alloy.
- There are many factors affecting fluidity, mainly solid particles of components, temperature and metal oxides, metal compounds and other pollutants in the alloy liquid, but the external fundamental factors are pouring temperature and pouring pressure (commonly known as pouring indenter). High and low.
- In actual production, in addition to the smelting process (refining and slag removal), the mold processability (sand mold permeability, metal mold venting and temperature) must be improved without affecting the alloy. Under the premise of casting quality, the pouring temperature is increased to ensure the fluidity of the alloy.
- Aluminum and aluminum alloys are processed into shaped materials, collectively referred to as aluminum, including sheets, strips, foils, tubes, rods, wires, profiles, and the like.
- Aluminum alloy material, high strength and light weight. The main welding processes are tungsten argon arc welding TIG, gas shielded welding MIG, friction stir welding FSW, resistance spot welding and so on.
- Aluminum alloy welding protection measures
- 1. Before welding, chemically and mechanically remove the oxides on the groove and surrounding parts of the workpiece and the surface of the wire. The order is chemical cleaning first, followed by mechanical grinding;
- 2. Use a qualified protective gas for protection during the welding process;
- 3. In the gas welding, the flux is used to continuously break the oxide film on the surface of the molten pool during the welding process.
- Difficulties in welding
- (1) Extremely easy to oxidize. In air, aluminum is easily oxidized to form a dense film of Al2O3 (thickness of about 0.1-0.2 μm) with a high melting point (about 2050 ° C), far exceeding the melting point of aluminum and aluminum alloy (about 600). °C or so). The density of alumina is 3.95-4.10g/cm3, which is about 1.4 times that of aluminum. The surface of alumina film is easy to adsorb moisture. When welding, it hinders the fusion of basic metals, and it is easy to form pores and slag. Defects such as unfusion cause a drop in weld performance.
- (2) It is easy to produce pores. The main cause of pores in the welding of aluminum and aluminum alloys is hydrogen. Since liquid aluminum can dissolve a large amount of hydrogen, solid aluminum hardly dissolves hydrogen. Therefore, when the temperature of the molten pool is rapidly cooled and solidified, hydrogen does not come out easily, and it is easy to weld. The pores gather to form pores. Hydrogen holes are difficult to avoid completely. There are many sources of hydrogen, such as hydrogen in an arc welding atmosphere, aluminum plates, and oxide film on the surface of the wire to absorb moisture in the air. Practice has proved that even if argon gas meets the requirements of GB/T4842, the purity is above 99.99%, but when the moisture content reaches 20ppm, a large number of tight pores will also appear. When the relative humidity of the air exceeds 80%, if no heating is taken When the measures are taken, the welds will have obvious pores. At the same time, the use of small current slow welding, increase the cooling time of the weld, and use the wire arc for the agitation of the molten pool, can better help the gas out of the molten pool.
- (3) The deformation of the weld and the tendency to form cracks are large. The coefficient of linear expansion and the rate of crystal shrinkage of aluminum are about twice as large as that of steel, which tends to cause large internal stresses of welding deformation, and the structure with higher rigidity will promote the generation of hot cracks.
- (4) The thermal conductivity of aluminum is large (pure aluminum 0.538 cal/cm.s. °C). It is about 4 times that of steel. Therefore, when welding aluminum and aluminum alloy, it consumes more heat than welded steel.
- (5) Evaporation of alloying elements. Aluminum alloys contain low-boiling elements (such as magnesium, zinc, manganese, etc.), which are easily evaporated and burned under the action of high-temperature arc, thus changing the chemical composition of the weld metal and degrading the weld performance.
- (6) Low temperature strength and low plasticity. The strength and plasticity of aluminum at low temperatures are low, which destroys the formation of weld metal and sometimes causes the weld metal to collapse and weld.
- (7) No color change. When aluminum and aluminum alloys change from solid to liquid, there is no obvious color change, making it difficult for the operator to grasp the heating temperature.
- The melting and casting of aluminum alloy is the main link in casting production. Strictly control the whole process of smelting and casting, and play an important role in preventing casting defects such as pinholes, inclusions, under-casting, cracks, pores and shrinkage. Since the aluminum melt has a large tendency to absorb hydrogen, has a strong oxidizing ability, and is easy to dissolve iron, it is necessary to take simple and cautious precautions in the smelting and casting process to obtain a high-quality casting.
- 1. Preparation and quality control of aluminum alloy charge
- In order to smelt high-quality aluminum melt, qualified raw materials should be used first. The raw materials must be scientifically managed and properly treated, otherwise the quality of the alloy will be seriously affected. Production practices have proved that the control of raw materials (including metal materials and auxiliary materials) will cause the castings to be scrapped in batches.
- (1) Raw materials must have qualified chemical composition and organization. The specific requirements are as follows:
- In addition to analyzing the main components and impurity content, the alloy ingots entering the factory are also inspected for low accompanying organization and fracture. Practice has proved that the use of aluminum liquid containing severe shrinkage cavities, pinholes, and air bubbles makes it difficult to obtain dense castings, and may even cause the entire furnace and the entire batch of castings to be scrapped.
- Some people have studied the influence of aluminum-silicon alloy ingot on the pinhole of aluminum alloy. It is found that there is no pinhole when using molten pure casting sand type test piece. When adding low-structure and unqualified aluminum-silicon alloy ingot, test piece pinhole Severe, and the grain size is large. The reason is due to the heritability of the material. The aluminum-silicon alloy and heredity increased with the increase of the content, and the amount of silicon reached 7%, which was genetically significant. Continue to increase the silicon content to the eutectic composition, and the heredity is slightly reduced. In order to solve the casting defects caused by the genetics of the charge, it is necessary to select aluminum ingots, intermediate alloys and other charge materials with high metallurgical quality. The specific criteria are as follows:
- (1) There should be no pinholes or stomata on the fracture
- The pinhole should be within three levels, and the local (not exceeding 25% of the tested area) should not exceed three levels. Those who exceed the third level must adopt the remelting method to reduce the pinhole. The remelting refining method is the same as the general aluminum alloy smelting, and the casting temperature should not exceed 660 ° C. For those aluminum ingots and alloy ingots with large original grain size, the lower ingot mold temperature should be used first to make them rapidly solidify and refine the crystal. grain.
- 2, charge treatment
- The charge should be sandblasted before use to remove rust, grease and other dirt on the surface. The aluminum alloy ingot and the metal-type returning material with a relatively clean surface can be left without blowing, but the iron filter and the inserts mixed in the charge should be eliminated. All the charge should be pre-filled before entering the furnace. Heat to remove the moisture attached to the surface and shorten the melting time by more than 3 hours.
- 3. Management and storage of charge
- Reasonable storage and management of the charge is important to ensure the quality of the alloy. The charge should be stored in a warehouse where the temperature does not change much and is dry.
- 2 , preparation of smelting tools
- (1) Commonly used iron shovel for casting aluminum alloy, and can also be welded with cast steel and steel plate.
- New sputum and long-lasting unused sputum should be blown sand before use and heated to 700--800 degrees for 2 - 4 hours to burn off moisture and combustible materials attached to the inner wall of the crucible. When the degree is below, carefully clean the inner wall of the crucible and spray the paint at a temperature not lower than 200 degrees.
- 预 Preheat to dark red (500-600 degrees) before use and keep it for more than 2 hours. Before the new smelting, it is best to melt a furnace of the same grade.
- (2) Preparation of the smelting tool
- Bell jar, pressure scoop, mixing spoon, ladle
- Ingot molds should be preheated before use, and coated with protective coating at 150 degrees---200 degrees temperature, and thoroughly dried, drying temperature is 200--400 degrees, holding time is more than 2 hours, after use The oxides and fluorides adhering to the surface should be thoroughly removed (preferably sandblasting).
- 3 , the control of the melting temperature
- The smelting temperature is too low, which is not conducive to the dissolution of alloying elements and the discharge of gases and inclusions, increasing the tendency to form segregation, cold separation, and under-casting, and the lack of heat in the riser, so that the casting cannot be properly fed. The data indicates that all aluminum alloys must have a melting temperature of at least 705 degrees and should be agitated. Excessive smelting temperature not only wastes energy, but more serious because the higher the temperature, the more hydrogen absorption, the coarser the crystal grains, the more severe the oxidation of aluminum, and the more serious the burning of some alloying elements, resulting in the mechanical properties of the alloy. The decline in casting properties and machinability deteriorates, the effect of deterioration treatment is weakened, and the airtightness of the casting is lowered.
- The production practice proves that the alloy liquid is rapidly heated to a higher temperature and reasonable agitation is carried out to promote the dissolution of all alloying elements (especially refractory metal elements), and the scum is removed to the pouring temperature, so that the degree of segregation The smallest, less hydrogen is dissolved, which is beneficial to obtain a uniform and dense alloy with high mechanical properties. Because the temperature of the aluminum melt is difficult to judge with the naked eye, no matter what type of melting furnace is used, the temperature measuring instrument should be used. temperature control. Temperature measuring instruments should be regularly checked and repaired. The thermowell should be cleaned periodically with a metal brush and coated with protective coating to ensure the accuracy of the temperature measurement results and the service life of the unit.
- 4 , the control of melting time
- In order to reduce the oxidation, absorption and dissolution of the aluminum melt, the residence time of the aluminum melt in the furnace should be shortened as much as possible, and the melting can be carried out quickly. From the start of melting to the completion of casting, sand casting is no more than 4 hours, metal casting is no more than 6 hours, and die casting is no more than 8 hours.
- In order to accelerate the smelting process, firstly add a medium-thickness, low-melting return charge and an aluminum-silicon intermediate alloy to form a molten pool as soon as possible at the bottom of the crucible, and then add a larger amount of recycled material and pure aluminum ingot to make them It can slowly immerse into the gradually expanding molten pool and melt quickly. After the main part of the charge is melted, an intermediate alloy having a relatively high melting point and a small amount is added, and the mixture is heated and stirred to accelerate the melting. Finally, the temperature is lowered and the alloy elements that are easily oxidized are pressed to reduce the loss.
- 5 , the transfer and pouring of the melt
- Although the density of solid alumina is similar to the density of the aluminum melt, after entering the interior of the aluminum melt, it will take a long enough time to sink to the bottom. The aluminum oxide film formed by oxidation of the aluminum melt is dense only on the side in contact with the aluminum melt, and the surface in contact with the air is loose and has a large number of small holes having a diameter of 60-100 A, and has a large surface area and adsorption. Strong, easy to adsorb in the water vapor, the tendency to float. Therefore, the difference in specific gravity between the oxide film and the aluminum melt is small, and it is mixed into the melt, and the floating and sinking speed is very slow, and it is difficult to remove from the melt, and pores are formed too much in the casting. Therefore, the key to transferring the aluminum melt is to minimize the agitation of the molten metal and minimize the contact of the melt with the air.
- When using the tilting type to transfer the melt, in order to avoid the mixing of the melt and the air, the ladle should be placed as far as possible against the nozzle and placed obliquely so that the melt flows down the side wall of the ladle without directly impacting the bottom., agitation, splashing, etc.
- The use of correct and reasonable casting methods is one of the important conditions for obtaining high quality castings. Production practice, pay attention to the following matters, is very effective in preventing and reducing casting defects.
- (1) Before pouring, carefully check the melt discharge temperature, ladle capacity and the dryness of the surface coating layer, and whether the preparation of other tools is satisfactory. The metal sprue cup is placed on the sand mold within 3 to 5 minutes before pouring. At this time, the temperature of the ladle is not higher than 150 degrees. The placement is too early or the temperature is too high, and a large amount of gas is trapped in the sprue. There is a danger of explosion when pouring.
- (2) It is not allowed to pour under the occasion of “over the wind”, and the melt is strongly oxidized and burned to cause defects such as oxidation inclusions in the casting.
- (3) When the melt is obtained from the crucible, the oxide scale or the flux layer on the surface of the melt should be gently peeled off with the bottom of the package, the ladle is slowly immersed in the melt, and the melt is taken from the wide mouth of the ladle. Then lift the ladle smoothly.
- (4) When the end pack is not flat, the step should be stable, the ladle should not be raised too high, and the molten metal surface in the ladle must be kept stable and not subject to being moved.
- (5) When pouring, the slag of the ladle should be cleaned so as not to bring slag, scale and the like into the mold during the pouring.
- (6) In the pouring, the melt flow is kept stable and cannot be interrupted, and the bottom hole of the mouth cannot be straightened. The gate should be filled from beginning to end, the liquid surface should not be turned, and the pouring speed should be properly controlled. Usually, the pouring start is slightly slower, the melt filling is smooth, then the speed is slightly faster, and the casting speed is kept substantially unchanged.
- (7) During the pouring process, the distance between the ladle nozzle and the gate is as close as possible, not exceeding 50 mm, so as to avoid excessive oxidation of the melt.
- (8) With a blocked gate, the blockage cannot be dialed too early. After the melt fills the gate, it is slowly and diagonally pulled out to prevent the melt from vortexing when it is injected into the runner.
- (9) It is not advisable to cast castings from the melt below 60 mm from the bottom of the crucible.
- Aluminum alloy casting (ZL)
- According to the main elements other than aluminum in the composition, silicon, copper, magnesium and zinc are classified into four categories, and the code numbers are 100, 200, 300, and 400, respectively.
- In order to obtain high-quality precision castings of various shapes and specifications, the aluminum alloy used for casting generally has the following characteristics.
- (1) Good fluidity with a narrow slotted portion of the slot
- (2) It has a lower melting point than ordinary metals, but it can meet the requirements of a large part of the situation.
- (3) Good thermal conductivity, the heat of molten aluminum can be quickly transferred to the mold, and the casting cycle is short.
- (4) Hydrogen and other harmful gases in the melt can be effectively controlled by treatment
- (5) There is no tendency for hot brittle cracking and tearing when casting aluminum alloy
- (6) Good chemical stability and strong corrosion resistance
- (7) It is not easy to produce surface defects, the surface of the casting has good surface finish and gloss, and it is easy to surface treatment.
- (8) The casting aluminum alloy has good processing performance, and can be used for casting production by die, hard mold, raw sand and dry sand mold, and investment gypsum casting mold. Vacuum casting, low pressure and high pressure casting, extrusion casting, and half can also be used. Solid casting, centrifugal casting and other methods are formed to produce various castings with different uses, different specifications and different properties.
- Cast aluminum alloys are widely used in cars, such as engine cylinder heads, intake manifolds, pistons, hubs, and steering booster housings.
- In the production process, aluminum alloys are prone to casting defects such as shrinkage cavities, blisters, pores and slag inclusions. How to repair defects such as blowholes in aluminum alloy castings? If it is repaired by equipment such as electric welding or argon welding, it is easy to cause side effects such as thermal deformation due to large heat release, and the repair welding requirements cannot be met.
- The cold welding repairing machine utilizes the high-frequency electric spark instantaneous discharge and the non-thermal surfacing principle to repair the casting defects. Since the area affected by the cold welding heat is small, the substrate is not annealed and deformed, and no cracks, no hard spots, and hardening are generated. Moreover, the welding strength is high, and the re-solidification of the filler and the substrate after melting at the same time, the combination is firm, and the grinding, milling, boring and the like can be processed, and the compaction does not fall off. Cold welding repair machine is an ideal method to repair small defects such as aluminum alloy pores and sand holes.
- All kinds of aircraft use aluminum alloy as the main structural material. The skin, beams, ribs, rafters, bulkheads and landing gear on the aircraft can be made of aluminum alloy. The amount of aluminum used varies depending on the application. The civilian machine that focuses on economic benefits is widely used because of the low price of aluminum alloy. For example, the aluminum alloy used in the Boeing 767 passenger aircraft accounts for 81% of the weight of the structure. Military aircraft relatively reduce the amount of aluminum required for good combat performance. For example, the F-15 high-performance fighter with a maximum flight speed of 2.5 Mach uses only 35.5% aluminum alloy. Some aluminum alloys have good low-temperature properties. They are not cold-brittle under -183~-253(2oc). They work in liquid hydrogen and liquid oxygen. They do not react chemically with concentrated nitric acid and dimethyl hydrazine. The welding properties are therefore a good material for making liquid rockets. The "Saturn" launching "Apollo" spacecraft No. 5 carrier rocket fuel tank, oxidizer tank, compartment section, interstage section, tail section and instrument compartment are all made of aluminum alloy.
- The shuttle's passenger compartment, front fuselage, mid fuselage, rear fuselage, vertical tail, flaps, elevons and horizontal tails are all made of aluminum alloy. The main structural materials of various artificial earth satellites and space probes are also aluminum alloys.
- The following are the application areas for the various models:
- 1050 Extrusion coils for food, chemical and brewing industries, various hoses, fireworks powder.
- 1060 requires high corrosion resistance and formability, but the strength is not high, and chemical equipment is its typical use.
- 1100 is used for processing parts that require good formability and high corrosion resistance but do not require high strength, such as chemical products, food industry equipment and storage containers, sheet metal parts, deep drawing or spinning concave vessels, Welding parts, heat exchangers, printing plates, nameplates, reflective appliances.
- 1145 Packaging and insulation foil, heat exchanger.
- 1199 Electrolytic capacitor foil, optical reflective deposition film.
- 1350 wires, conductive strands, bus bars, transformer strips.
- 2011 screws and machined products requiring good cutting performance.
- 2014 is used in applications where high strength and hardness (including high temperature) are required. Aircraft heavy duty, forgings, slabs and extruded materials, wheels and structural components, multi-stage rocket first-stage fuel tanks and spacecraft parts, truck frames and suspension system parts.
- 2017 is the first 2XXX series alloy to be used in industrial applications. It has a narrow range of applications, mainly for rivets, general mechanical parts, structural and transport structural parts, propellers and accessories.
- 2024 Aircraft structures, rivets, missile components, truck hubs, propeller components and other structural components.
- 2036 car body sheet metal parts.
- 2048 Aerospace structural components and weapons structural parts.
- 2124 Aerospace structural components.
- 2218 aircraft engine and diesel engine piston, aircraft engine cylinder head, jet engine impeller and compressor ring.
- 2219 Space rocket welding oxidizer tank, supersonic aircraft skin and structural parts, operating temperature -270 ~ 300 °C. Good weldability, high fracture toughness, and high resistance to stress corrosion cracking in the T8 state.
- 2319 Welding electrode and filler solder for 2219 alloy.
- 2618 die forgings and free forgings. Piston and aero engine parts.
- 2A01 Structural rivets with an operating temperature of 100 ° C or less.
- 2A02 Axial compressor blades for turbojet engines operating at temperatures from 200 to 300 °C.
- 2A06 Aircraft structure rivets with an operating temperature of 150~250°C and an operating temperature of 125~250°C.
- 2A10 is higher in strength than 2A01 alloy and is used to manufacture aircraft structural rivets with an operating temperature of 100 °C or less.
- Medium-strength structural parts, propeller blades, transportation vehicles and building structural parts of the 2A11 aircraft. Medium strength bolts and rivets for aircraft.
- 2A12 Aircraft skins, bulkheads, ribs, spars, rivets, etc., construction and transportation structural components.
- 2A14 Free forgings and die forgings with complex shapes.
- 2A16 Spacecraft parts with a working temperature of 250~300°C, welded containers and airtight cockpits operating at room temperature and high temperature.
- 2A17 Aircraft parts with a working temperature of 225~250°C.
- 2A50 Medium-strength part with complex shape.
- 2A60 aircraft engine compressor wheel, wind guide, fan, impeller, etc.
- 2A70 aircraft skin, aircraft engine piston, wind deflector, roulette, etc.
- 2A80 Aero Engine Compressor Blades, Impellers, Pistons, Rings and Other Parts with High Operating Temperatures.
- 2A90 aero engine piston.
- 3003 is used for processing parts parts that require good formability, high corrosion resistance, or require both these properties and work with higher strength than 1XXX series alloys, such as kitchen utensils, food and chemical products. With storage devices, tanks, tanks for transporting liquid products, various pressure vessels and pipes processed in thin plates.
- The 3004 all-aluminum can body requires higher strength parts than the 3003 alloy, chemical production and storage devices, sheet metal parts, construction parts, construction tools, and various lamp parts.
- 3105 Room partitions, baffles, movable floor panels, gutters and downpipes, sheet forming parts, caps, stoppers, etc.
- 3A21 Aircraft fuel tank, oil pipeline, rivet wire, etc.; industrial materials such as building materials and food.
- Similar to the 3003 alloy, the 5005 has medium strength and good corrosion resistance. Used as conductors, cookware, instrument panels, shells and architectural trims. The anodized film is brighter than the oxide film on the 3003 alloy and is consistent with the hue of the 6063 alloy.
- 5050 sheet can be used as the inner liner of refrigerator and refrigerator, automobile air pipe, oil pipe and agricultural irrigation pipe; it can also process thick plate, pipe, bar, profile and wire.
- 5052 This alloy has good formability, corrosion resistance, candle resistance, fatigue strength and medium static strength. It is used in the manufacture of aircraft fuel tanks, oil pipes, and sheet metal parts for transportation vehicles and ships. Instruments, street lamp brackets and rivets, hardware products, etc.
- 5056 Magnesium alloy and cable sheath rivets, zippers, nails, etc.; aluminum-clad wire is widely used in the processing of agricultural insect traps, and other occasions requiring high corrosion resistance.
- 5083 For applications requiring high corrosion resistance, good weldability and moderate strength, such as ship, automotive and aircraft welded parts; pressure vessels requiring severe fire protection, refrigeration, television towers, drilling equipment, transportation Transportation equipment, missile components, armor, etc.
- 5086 For applications requiring high corrosion resistance, good weldability and moderate strength, such as ships, automobiles, airplanes, cryogenic equipment, television towers, drilling rigs, transportation equipment, missile components and decks.
- 5154 Welded structures, storage tanks, pressure vessels, ship structures and offshore installations, transport tanks.
- 5182 Sheets are used to machine cans, car body panels, control panels, reinforcements, brackets and more.
- 5252 Used to make decorative parts with high strength, such as decorative parts for automobiles. It has a bright and transparent oxide film after anodization.
- 5254 Hydrogen peroxide and other chemical product containers.
- 5356 Aluminum-magnesium alloy welding rod and welding wire with a magnesium content greater than 3%.
- 5454 welded structure, pressure vessel, marine facility piping.
- 5456 armor plate, high-strength welded structure, storage tank, pressure vessel, ship material.
- 5457 Decorative parts for automobiles and other equipment that have been polished and anodized.
- 5652 Hydrogen peroxide and other chemical product storage containers.
- 5657 Decorative parts for automobiles and other equipment that are polished and anodized, but in any case must ensure that the material has a fine grain structure.
- 5A02 Aircraft fuel tanks and conduits, welding wire, rivets, marine structural parts.
- 5A03 Medium strength welded construction, cold stamped parts, welded containers, welding wire, can be used to replace 5A02 alloy.
- 5A05 Welded structural parts, aircraft skin skeleton.
- 5A06 Welded structure, cold forged parts, welded parts for welded containers, aircraft skin parts.
- 5A12 Welded structural parts, bulletproof deck.
- 6005 extruded profiles and tubes for structural parts requiring a height greater than 6063 alloy, such as ladders, TV antennas, etc.
- 6009 car body panels.
- 6010 Sheet: Car body.
- 6061 requires various industrial structures with certain strength, weldability and high corrosion resistance, such as pipes, rods, profiles, etc. for the manufacture of trucks, tower buildings, ships, trams, fixtures, mechanical parts, precision machining, etc. Plate.
- 6063 Building profiles, irrigation pipes and extruded materials for vehicles, stands, furniture, fences, etc.
- 6066 Forgings and welded structural extruded materials.
- 6070 Heavy-duty welded construction and extruded materials and pipes for the automotive industry.
- 6101 High-strength bars, electric conductors and radiator materials for buses.
- 6151 is used for die forging crankshaft parts, machine parts and production rolling rings for both good forgeability, high strength and good corrosion resistance.
- 6201 High-strength conductive rods and wires.
- 6205 Thick plates, pedals and high impact resistant extrusions.
- 6262 Requires high-stress parts with thread resistance superior to those of the 2011 and 2017 alloys.
- 6351 Extrusion structural parts of vehicles, conveying pipes for water, oil, etc.
- 6463 Construction and various appliance profiles, as well as automotive decorative parts with a bright surface after anodizing.
- 6A02 Aircraft engine parts, complex forgings and die forgings.
- 7005 extruded material for the manufacture of welded structures that require both high strength and high fracture toughness, such as trusses, rods, and containers for transportation vehicles; large heat exchangers, and cannot be solidified after welding Parts; can also be used to make sports equipment such as tennis rackets and softball bats.
- 7039 Freezer containers, cryogenic instruments and storage tanks, fire pressure equipment, military equipment, armor plates, missile devices.
- 7049 Forging parts with the same static strength as the 7079-T6 alloy and requiring high resistance to stress corrosion cracking, such as aircraft and missile parts - landing gear cylinders and extrusions. The fatigue performance of the part is roughly equal to that of the 7075-T6 alloy, and the toughness is slightly higher.
- 7050 Medium and heavy plates, extrusions, free forgings and die forgings for aircraft structural parts. The requirements for the manufacture of such parts are: resistance to spalling corrosion, stress corrosion cracking, fracture toughness and fatigue resistance.
- 7072 air conditioner aluminum foil and ultra-thin strip; 2219, 3003, 3004, 5050, 5052, 5154, 6061, 7075, 7475, 7178 alloy sheet and tube coating.
- 7075 Used in the manufacture of aircraft structures and futures. He requires high-strength structural parts and molds with high strength and corrosion resistance.
- 7175 High-strength structural for forging aircraft. T736 material has good comprehensive properties, namely high strength, anti-flaking corrosion and stress corrosion cracking resistance, fracture toughness and fatigue strength.
- 7178 Parts required for the manufacture of aerospace vehicles with high compressive yield strength.
- 7475 aluminum and uncoated aluminum plates for the fuselage, wing frames, purlins, etc. Other parts that require both high strength and high fracture toughness.
- 7A04 aircraft skins, screws, and force members such as beam girders, bulkheads, ribs, landing gear, etc.
- Aluminum alloy profile
- The aluminum and aluminum alloy materials obtained by extrusion processing can be used for plates, rods and various shaped profiles, and can be widely applied to new materials in the fields of construction, transportation, transportation, aerospace and the like.
- Aluminum alloy sheets can be divided into two categories: non-painted products and painted products according to the surface treatment.
- 1) Non-painted products
- (1) It can be divided into hammered aluminum plate (irregular pattern), embossed plate (with regular pattern) and pre-passivation, anodized aluminum surface treatment plate.
- (2) These products are not painted on the surface of the board, and the appearance of the surface is not high and the price is low.
- 2) Paint products
- (1) Classification:
- According to the painting process, it can be divided into: spray plate products and pre-roll coated plates;
- According to the type of paint can be divided into: polyester, polyurethane, polyamide, modified silicon, epoxy resin, fluorocarbon and so on.
- (2) Among the various coatings, the main performance difference is the resistance to ultraviolet light from the sun. The most common coating on the front side is fluorocarbon paint (PVDF), which has strong resistance to UV rays; Or epoxy coating as a protective lacquer. In addition, a protective film that can be peeled off can be attached to the front side.
- 2. Aluminum composite panel
- The aluminum-plastic composite panel is a new material made of a surface treated and coated with 3003 aluminum-manganese alloy, 5005 aluminum-magnesium alloy sheet as the surface, PE plastic as the core layer and polymer adhesive film processed through a series of processes. It not only retains the main characteristics of the original constituent materials (aluminum alloy sheet, non-metallic polyethylene plastic), but also overcomes the shortcomings of the original constituent materials, and thus obtains many excellent material properties. Product features: colorful and decorative, weathering, corrosion resistance, shock resistance, fire, moisture, sound insulation, heat insulation, shock resistance, light weight, easy processing and easy to handle and install.
- Aluminum composite panel specifications:
- Thickness: 3mm, 4mm, 6mm, 8mm
- Width: 1220mm, 1500mm
- Length: 1000mm, 2440mm, 3000mm, 6000mm
- Aluminum composite panel standard size: 1220*2440mm
- Aluminum-plastic panel use: It can be applied to the decoration of curtain wall, interior and exterior walls, foyer, restaurant, shop, conference room, etc. It can also be used for the reconstruction of old buildings, used as the surface of counters, furniture, and the inner and outer walls of vehicles.
- 3. Aluminum veneer
- The aluminum veneers are made of high-quality aluminum alloys made by world-famous large enterprises, and then refined by surface spraying with American PPG or Aksu PVDF fluorocarbon baking varnish. The aluminum veneers are mainly composed of panels, reinforcing bones and hanging ears.
- Aluminum veneer features: light weight, good rigidity, high strength, non-combustibility, good fire resistance, good processing technology, wide color selection, excellent decorative effect, easy recycling, and environmental protection.
- Aluminum veneer applications: building curtain wall, column beam, balcony, partition bag decoration, interior decoration, advertising signs, vehicles, furniture, exhibition stands, instrument housing, subway shipping tools.
- 4. Aluminum honeycomb panel
- The aluminum honeycomb panel adopts composite honeycomb structure, and is made of high quality 3003H24 alloy aluminum plate or 5052AH14 high manganese alloy aluminum plate as substrate.
- Aluminum honeycomb panels are not available in standard sizes. All panels are custom-made according to the design drawings. They are widely used in exterior wall decoration (especially for high-rise buildings) interior ceilings, wall partitions, doors and insulated compartments., billboards and other fields. This product will inject green, environmental protection and energy saving fresh activity into China's building materials market.
- 5. Aluminum honeycomb perforated sound-absorbing ceiling panel
- The structure of the aluminum honeycomb perforated sound-absorbing ceiling plate is a perforated aluminum alloy panel and a perforated back plate, and is directly bonded to an aluminum honeycomb sandwich structure by a high-quality adhesive and an aluminum honeycomb core, and a sound-absorbing cloth is attached between the honeycomb core and the panel and the back plate. Since the honeycomb core in the honeycomb aluminum plate is divided into a plurality of closed cells, the air flow is prevented, the sound waves are hindered, the sound absorption coefficient is increased (up to 0.9 or more), and the strength of the plate itself is improved, so that the size of the single plate can be To achieve greater, further increase the freedom of design. According to the indoor acoustic design, different perforation rate design can be carried out to control the sound absorption coefficient of the combined structure within a certain range, which not only achieves the design effect, but also can reasonably control the cost. By controlling the perforation aperture and hole spacing, and changing the perforation rate according to the customer's requirements, the maximum perforation rate is
- 6. Fluorocarbon aluminum plate
- 6.1) Fluorocarbon spray plate
- (1) Fluorocarbon spray coatings are divided into two coating systems, three coating systems and four coating systems. Generally, multi-layer coating systems should be used.
- Two-coating system: consisting of 5-10 μm fluorocarbon primer and 20-30 μm fluorocarbon topcoat. The total thickness of the film layer is generally not less than 35 μm. Can only be used in normal environments.
- Three-coating system: consisting of 5-10 μm fluorocarbon primer, 20-30 μm fluorocarbon paint and 10-20 μm fluorocarbon varnish. The total thickness of the film layer is generally not less than 45 μm. It is suitable for severe environmental pollution, industrial areas and coastal areas.
- Four-coat system: There are two types of four-coat system. One is to add a 20μm fluorocarbon intermediate paint between the primer and the top coat when using large-particle aluminum powder pigment; the other is to add a polyamide and polyurethane blend between the primer and the top coat. The dense coating improves the corrosion resistance and increases the service life of the fluorocarbon aluminum plate. Because the general fluorocarbon paint is a sponge structure with pores, it cannot prevent the positive and negative ions in the air from penetrating freely to the base of the metal plate. Therefore, this coating system is more suitable for severe environmental pollution, industrial areas and coastal areas.
- (2) Curing of fluorocarbon baking varnish: It should be baked with a few coats to make each layer of lacquer completely cured, forming good adhesion, corrosion resistance and fading resistance, avoiding more baking and less baking.
- (3) When selecting fluorocarbon lacquered aluminum panels, attention should be paid to the brand and main technical indicators of fluorocarbon lacquer, and the fluororesin content should be ≥ 70%.
- 6.2) Fluorocarbon pre-roll coated aluminum sheet
- (1) The design idea of pre-rolled aluminum sheet is to combine as many material and process advantages as possible
- (2) The fluororesin content can be up to 80%.
- (3) The thickness of the coating is generally 25 μm.
|Parameter name||Indicator requirements|
|Modulus of elasticity (kN/cm^2)||6900|
|Thermal conductivity (W/(m·°C))||214|
|Longitudinal thermal expansion coefficient (mm/(m·°C))||24×10-3|
|Melting point (°C)||650|
- Note: Applicable to 3004 and 3015 aluminum manganese magnesium alloy
What Links Here
- Chen Zhenhua. Modern Powder Metallurgy Technology 2nd Edition: Chemical Industry Press, March 2013: page 246
- Jiang Minhua. Amazing new material: Shandong Science and Technology Press, October 2013: page 18
- (US) JRDAVIS (Joseph R. Davis). Metal Handbook Volume Book Volume 2nd Edition: Mechanical Industry Press, March 2014: Page 83