Introduction and classification of aluminum alloys

Aluminum Alloy Series Introduction

Aluminum Alloy Overview: Aluminum alloy is the most widely used type of non-ferrous metal structural material in industry. It has been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industries. With the rapid development of science and technology and industrial economy in recent years, the demand for aluminum alloy welded structural parts has increased, which has led to in-depth research on the weldability of aluminum alloys. The wide application of aluminum alloys has promoted the development of aluminum alloy welding technology. At the same time, the development of welding technology has expanded the application field of aluminum alloys. Therefore, aluminum alloy welding technology is becoming one of the research hotspots.

aluminum vs iron

The density of pure aluminum is small (ρ=2.7g/cm3), which is about 1/3 of iron. The melting point is low (660℃). Aluminum is a face-centered cubic structure, so it has high plasticity (δ: 32~40%, ψ: 70~90%), easy to process, and can be made into various profiles and plates. Good corrosion resistance; but the strength of pure aluminum is very low, and the annealing state σb value is about 8kgf/mm2, so it is not suitable for structural materials. Through long-term production practice and scientific experiments, people gradually strengthened it by adding alloy elements and using heat treatment methods, thus obtaining a series of aluminum alloys. The alloy formed by adding certain elements can have high strength while maintaining the advantages of pure aluminum such as light weight, and the σb value can reach 24-60kgf/mm2. This makes its “specific strength” (the ratio of strength to specific gravity σb/ρ) better than many alloy steels, making it an ideal structural material, widely used in machinery manufacturing, transportation machinery, power machinery and aviation industry. The fuselage, skin, compressor, etc. of aircraft are often made of aluminum alloy to reduce their own weight. The use of aluminum alloy instead of steel plate material for welding can reduce the weight of the structure by more than 50%. Aluminum alloy has low density, but relatively high strength, close to or exceeding high-quality steel, good plasticity, can be processed into various profiles, has excellent electrical conductivity, thermal conductivity and corrosion resistance, and is widely used in industry, second only to steel in terms of usage. Aluminum alloys are divided into two categories: cast aluminum alloys, which are used in the cast state; deformed aluminum alloys, which can withstand pressure processing. Aluminum alloys can be processed into various forms and specifications. It is mainly used to manufacture aviation equipment, doors and windows for buildings, etc. Aluminum alloys can be divided into deformable aluminum alloys and cast aluminum alloys according to the processing method. Deformable aluminum alloys are further divided into non-deformable aluminum alloys, non-heat-treatable strengthening aluminum alloys and heat-treatable strengthening aluminum alloys. Non-heat-treatable strengthening types cannot improve mechanical properties through heat treatment, and can only be strengthened through cold working deformation. It mainly includes high-purity aluminum, industrial high-purity aluminum, industrial pure aluminum, and rust-proof aluminum. Heat-treatable strengthening aluminum alloys can improve mechanical properties through heat treatment methods such as quenching and aging. It can be divided into hard aluminum, forged aluminum, super-hard aluminum, and special aluminum alloys. Some aluminum alloys can be heat-treated to obtain good mechanical properties, physical properties, and corrosion resistance.

Cast aluminum alloys can be divided into aluminum-silicon alloys, aluminum-copper alloys, aluminum-magnesium alloys, aluminum-zinc alloys and aluminum rare earth alloys according to their chemical composition. Among them, aluminum-silicon alloys include simple aluminum-silicon alloys (which cannot be strengthened by heat treatment, have low mechanical properties and good casting properties) and special aluminum-silicon alloys (which can be strengthened by heat treatment, have high mechanical properties and good casting properties).

Classification of aluminum alloys

Series 1000: 1000 series aluminum alloys represent 1050, 1060, and 1100 series. Among all series, 1000 series is the one with the highest aluminum content. The purity can reach more than 99.00%. Since 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 conventional industry. Most of the 1050 and 1060 series are currently circulating on the market. The 1000 series aluminum plate determines the minimum aluminum content of this series based on the last two Arabic numerals. For example, the last two Arabic numerals of the 1050 series are 50. According to the international brand naming principle, the aluminum content must reach more than 99.5% to be a qualified product. my country’s aluminum alloy technical standards (gB/T3880-2006) also clearly stipulate that the aluminum content of 1050 reaches 99.5%. For the same reason, the aluminum content of 1060 series aluminum plates must reach more than 99.6%.

Series 2000: 2000 series aluminum alloys represent 2024, 2A16 (LY16), 2A02 (LY6). The characteristics of 2000 series aluminum plates are high hardness. The characteristics of the plates are high hardness, among which the copper content is the highest, about 3-5%. 2000 series aluminum bars belong to aviation aluminum materials and are not commonly used in conventional industries.

Series 3000: 3000 series aluminum alloys represent 3003 and 3A21. my country’s 3000 series aluminum plate production process is relatively excellent. 3000 series aluminum bars are mainly composed of manganese elements. The content is between 1.0-1.5, which is a series with good anti-rust function.

3003 aluminum alloys diamond sheet

Series 4000: 4000 series aluminum bars represent 4A01. 4000 series aluminum plates belong to the series with high silicon content. Usually the silicon content is between 4.5-6.0%. It belongs to building materials, mechanical parts, forging materials, welding materials; low melting point, good corrosion resistance, product description: It has the characteristics of heat resistance and wear resistance.

5000 series: 5000 series aluminum alloy represents 5052, 5005, 5083, 5A05 series. 5000 series aluminum rod belongs to the more commonly used alloy aluminum plate series, the main element is magnesium, and the magnesium content is between 3-5%. It can also be called aluminum-magnesium alloy. The main characteristics are low density, high tensile strength and high elongation. The weight of aluminum-magnesium alloy is lower than other series under the same area. It is also widely used in conventional industries. In my country, 5000 series aluminum plate belongs to one of the more mature aluminum plate series.

6000 series: 6000 series aluminum alloy represents 6061. It mainly contains two elements, magnesium and silicon, so it concentrates the advantages of 4000 series and 5000 series. 6061 aluminum is a cold-treated aluminum forging product, suitable for applications with high requirements for corrosion resistance and oxidation resistance. Good usability, easy coating, good processability.

7000 series: 7000 series aluminum alloy represents 7075, which mainly contains zinc. It also belongs to the aviation series, is an aluminum-magnesium-zinc-copper alloy, is a heat-treatable alloy, belongs to a super-hard aluminum alloy, and has good wear resistance. At present, it basically relies on imports, and my country’s production technology needs to be improved.

8000 series: 8000 series aluminum alloys are more commonly used for 8011, which belongs to other series. Most of them are used for aluminum foil, and are not commonly used in the production of aluminum bars.

9000 series: 9000 series aluminum alloys are spare alloy series.