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Aluminum Raw Materials Buying Guide
Aluminum, as a metal material widely used in modern industry and daily life, is highly favored for its light weight, high strength, good electrical conductivity, thermal conductivity and corrosion resistance. From the high-tech field of aerospace to the daily scenes of building decoration, to the electronic products, packaging and other industries, aluminum is everywhere.
Jun 17th,2025
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一. Types and characteristics of aluminum raw materials
(I) Classification by purity
1. Pure aluminum: The purity can reach more than 99%, among which the 1000 series is a typical representative, such as 1050 aluminum, which contains 99.5% aluminum. Pure aluminum has excellent electrical and thermal conductivity, and is widely used in fields such as wires, cables, and heat exchangers that have strict requirements on electrical and thermal conductivity. At the same time, it has good corrosion resistance and is also used in some occasions that do not require high strength but require good corrosion resistance, such as food packaging aluminum foil. However, pure aluminum is soft and has relatively low strength.
2. Industrial high-purity aluminum: The aluminum content is between 99.85% and 99.90%. Compared with pure aluminum, the impurity content is lower. It is more common in some special industrial applications that have high requirements for material purity and require a certain strength, such as the manufacture of high-precision electronic components in the electronics industry.
3. High-purity aluminum: The aluminum content is as high as 99.93% - 99.999%, with extremely excellent physical and chemical properties. It is often used in high-end fields with almost stringent requirements on material performance, such as the manufacturing of key components in aerospace, high-precision instruments, etc., to ensure the reliability and stability of the product under extreme conditions.
(II) Classification by alloy composition
1.1000 series pure aluminum: In addition to the good electrical conductivity, thermal conductivity and corrosion resistance mentioned above, it is the most widely used pure aluminum series in conventional industry because of its relatively simple production process and low cost. It can be made into various basic materials such as plates, pipes, wires, etc. to meet the diversified processing needs of different industries.
2.2000 series aluminum-copper alloy: represented by 2024 and 2A12 (i.e. LY12), the copper content is about 3-5%. The outstanding features of this series of aluminum alloys are high hardness, high strength, and good cutting performance. It is particularly suitable for manufacturing structural parts with extremely high strength requirements, such as aircraft beams, landing gear and other key components in the aviation field. However, its corrosion resistance is relatively weak, and special surface protection treatment is often required when it is used.
3.3000 series aluminum-manganese alloy: mainly represented by 3003 and 3A21, the manganese content is between 1.0-1.5. This series of aluminum alloys has good anti-rust properties, as well as good formability and weldability. They are often used to manufacture parts that require good formability and corrosion resistance, such as automobile fuel tanks, some structural parts of ships, and some modeling parts in architectural decoration.
4.5000 series aluminum-magnesium alloy: Typical grades include 5052, 5083, 5A06, etc., with magnesium content between 3-5%. This series of aluminum alloys has low density, high tensile strength, good elongation, excellent fatigue strength, and cannot be strengthened by heat treatment. Under the same area, its weight is lower than many other series of aluminum alloys, and it is widely used in conventional industries and some weight-sensitive fields, such as automobile body manufacturing and ship decks.
5.6000 series aluminum-magnesium-silicon alloy: Common 6061, 6063, and 6082 belong to this series, and the main alloying elements are magnesium and silicon. This is a heat-treatable and strengthened alloy with excellent formability, weldability, and machinability, as well as medium strength. In the annealed state, it can still maintain good operability, especially suitable for applications with high requirements for corrosion resistance and oxidation resistance, such as building door and window frames, curtain wall profiles, etc. It is one of the most widely used aluminum alloy series in the construction industry.
6.7000 series aluminum-zinc alloy: represented by 7075, the main alloying element is zinc, and it also belongs to the aviation series aluminum alloy, which is an aluminum-magnesium-zinc-copper alloy. This series of aluminum alloys can be strengthened by heat treatment, and is a super-hard aluminum alloy with good wear resistance. It is often used to manufacture parts with extremely high strength and hardness requirements, such as aircraft wings and high-performance wheels of automobiles. However, its corrosion resistance is poor, and special protective measures are usually required to prevent corrosion during use.
(III) Classification by product form
1. Aluminum sheet: uniform thickness, smooth surface, good plasticity and processing performance. In building exterior wall decoration, different surface treatment processes can be used to present a variety of appearance effects, adding a sense of modernity and beauty to the building; in the field of automobile body manufacturing, aluminum sheet can effectively reduce the weight of the body, while ensuring the strength and safety of the body structure, helping to improve the fuel economy and handling performance of the car.
2. Aluminum pipe: There are many shapes such as round pipes and square pipes, with high strength and good compressive resistance. In furniture manufacturing, aluminum pipes are often used to make the frames of tables and chairs, which not only ensures the stability of the furniture, but also gives it a stylish and simple appearance; in terms of building structure support, aluminum pipes can be used as supporting components of lightweight structures, while meeting the strength requirements of the building structure, realizing the lightweight design of the building.
3. Aluminum profiles: Various complex cross-sectional shapes are made through extrusion technology, which can accurately meet the design requirements of different products. In the manufacture of building components such as doors, windows, and curtain walls, aluminum profiles are the core material. Their good thermal insulation and sound insulation properties as well as a variety of surface treatment effects make them an ideal choice for energy saving and aesthetics in modern buildings. In the field of electronic equipment, aluminum profiles are also often used to make components such as radiators. Their good thermal conductivity can effectively dissipate the heat generated during the operation of the equipment and ensure the stable operation of the equipment.
二. Clarify usage scenarios and requirements
(I) Construction field
1. Doors, windows and curtain walls: If used for the frame production of doors, windows and curtain walls, 6000 series aluminum-magnesium-silicon alloys are ideal, such as 6063, 6061, etc. These alloys have medium strength, good formability and corrosion resistance, and can meet the requirements of doors, windows and curtain walls for structural strength and appearance quality. At the same time, its surface can be anodized, electrophoretic painted, powder sprayed and other treatments to obtain rich colors and excellent weather resistance, improving the overall beauty and service life of the building.
2. Architectural decoration: For indoor and outdoor decorative lines, ceilings, wall decorative panels, etc., pure aluminum plates or 3000 series aluminum-manganese alloy plates are more suitable. The high reflectivity and good plasticity of pure aluminum plates can create a simple and bright decorative effect; the 3000 series alloys can be made into various complex shapes due to their good rust resistance and formability to meet the needs of different decorative styles.
3. Structural support: In some lightweight building structures, such as the roof structure of gymnasiums and exhibition halls, pipes or profiles made of 5000 series aluminum-magnesium alloys or 6000 series alloys with higher strength can be selected. These materials can effectively reduce the weight of the building and reduce the cost of infrastructure construction while ensuring structural strength. They also have good corrosion resistance and are suitable for long-term outdoor use.
(II) Transportation field
1. Aerospace: The performance requirements of materials in the aerospace field are extremely stringent. 2000 series aluminum-copper alloys and 7000 series aluminum-zinc alloys are commonly used materials. Alloys such as 2024 and 7075 have the characteristics of high strength and low density, which can meet the needs of aircraft structural parts to reduce weight while bearing huge loads, and improve the fuel efficiency and flight performance of aircraft. In addition, these alloys must undergo strict quality inspections and special heat treatment processes to ensure their reliability and safety in extreme environments.
2. Automobile manufacturing: In order to achieve the goals of energy conservation, emission reduction and performance improvement, the automobile industry is increasingly using aluminum alloy materials. 5000 series aluminum-magnesium alloys are often used in automobile body panels, such as doors and engine hoods. Due to their low density and high strength, they can effectively reduce the weight of the car body while ensuring the impact resistance of the car body. 6000 series alloys are widely used in automobile chassis components, wheels, etc. Their good machinability and corrosion resistance can meet the complex manufacturing process and long-term use requirements of automobile parts. In addition, some high-performance cars will also use some 2000 series alloys to manufacture key structural parts to improve the overall performance of the car.
(III) Electronic equipment field
1. Electronic product housing: In order to meet the needs of electronic products for thinness, beauty and good heat dissipation, 6000 series aluminum-magnesium-silicon alloys and some 5000 series aluminum-magnesium alloys are widely used in the manufacture of mobile phone housings, laptop computer housings and other products. These alloys have good formability and surface treatment performance, and can be made into various exquisite appearance shapes through processes such as die casting and stamping. At the same time, their good thermal conductivity helps to quickly dissipate the heat generated inside electronic products and ensure the stable operation of the equipment.
2. Radiator: In the heat dissipation system of electronic equipment, aluminum is the preferred material for making radiators due to its excellent thermal conductivity. Radiators made of pure aluminum or 6000 series alloys can quickly conduct the heat generated by electronic components and dissipate the heat to the surrounding environment through structures such as heat dissipation fins, ensuring that electronic equipment works within the normal temperature range and extending the service life of the equipment.
(IV) Packaging field
1. Food packaging: Aluminum foil is an important material for food packaging, mainly made of pure aluminum. Pure aluminum foil has good barrier properties, can effectively block the invasion of oxygen, water vapor and odor, and protect the freshness and quality of food. At the same time, aluminum foil is non-toxic and odorless, will not react chemically with food, meets the hygiene standards of food packaging, and is widely used in the packaging of chocolate, candy, medicine, etc.
2. Beverage packaging: Aluminum cans are a common form of beverage packaging, usually made of 3000 series aluminum-manganese alloy. This series of alloys has good formability and corrosion resistance, and can be made into cans with regular shapes and reliable strength through stamping, stretching and other processes. In addition, aluminum cans are light in weight and easy to recycle, which conforms to modern environmental protection concepts and occupies an important position in the beverage packaging market.
三. Evaluate material quality
(I) Check quality certification documents
Formal aluminum raw material suppliers should provide detailed quality certification documents, including quality inspection reports, chemical composition analysis reports, mechanical properties test reports, etc. In the chemical composition analysis report, it is necessary to carefully check whether the types and contents of alloying elements meet the corresponding standards and grades. For example, for 6063 aluminum alloy, its magnesium content should be between 0.45-0.9%, silicon content between 0.20-0.60%, and aluminum as the remainder. The mechanical properties test report should show key indicators such as tensile strength, yield strength, and elongation of the material. These indicators directly reflect the strength and toughness of the material and should match the standard performance range of the selected grade. By strictly reviewing the quality certification documents, it can be preliminarily judged whether the aluminum raw materials meet the required quality standards.
(II) Check the appearance quality
1. Surface flatness: The surface of high-quality aluminum raw materials should be flat and smooth, without obvious bumps, wrinkles or deformation. For aluminum plates, they can be placed on a horizontal platform and measured by naked eye or using a flatness detection tool to ensure that the flatness error of the plate surface is within the allowable range. For aluminum profiles and pipes, check whether their cross-sectional shapes are regular and whether the surface has defects such as distortion and bending, so as not to affect subsequent processing and use.
2. Surface defects: Carefully observe whether there are scratches, sand holes, bubbles, cracks and other defects on the surface of aluminum raw materials. Scratches may reduce the strength and corrosion resistance of the material, sand holes and bubbles will affect the appearance and uniformity of the internal structure of the material, and cracks are serious quality problems that may cause the material to break during use. For aluminum materials with coatings or oxide films on the surface, it is also necessary to check whether the coating or oxide film is uniform and firm, and whether there is any shedding or peeling.
3. Color consistency: If the aluminum raw material has undergone surface treatment, such as anodizing, spraying, etc., ensure that its color is uniform. Color differences may mean that there are problems with the surface treatment process, affecting the aesthetics and overall quality of the material. When purchasing in bulk, you should randomly select multiple samples for comparison to check the color consistency.
(III) Conduct simple physical tests
1. Hardness test: A hardness tester can be used to test the hardness of aluminum raw materials. Different types and grades of aluminum alloys have corresponding hardness ranges. For example, the hardness of 6063 aluminum alloy is generally between 8 and 12HW. By testing the hardness, it is possible to preliminarily determine whether the alloy composition and heat treatment state of the material meet the requirements. In the absence of a professional hardness tester, a simple scratch test method can also be used. Use an object with known hardness (such as a pencil lead) to gently scratch the surface of the aluminum material, observe the depth of the scratch, and compare it with the standard hardness reference to roughly evaluate the hardness of the material.
2. Density test: The density of aluminum is about 2.7g/cm³. The density of different alloys will vary slightly due to differences in composition. By measuring the density of aluminum raw materials and comparing it with the theoretical density, it can be determined whether too many impurities or other metal elements are mixed into the material, thereby affecting the performance of the material. The density test can be carried out by simple methods such as the water displacement method. First, measure the mass of the material, then immerse it completely in water, measure the volume of the water displaced, and calculate the actual density of the material according to the density formula.
3. Conductivity test: For aluminum raw materials used in the electrical field, such as aluminum for wires and cables, its conductivity is a key performance indicator. A professional resistance tester can be used to measure the resistance value of aluminum materials. The lower the resistance value, the better its conductivity. In actual testing, attention should be paid to eliminating interference from factors such as contact resistance to ensure the accuracy of the test results. At the same time, the test results can be compared with the resistance value of standard aluminum materials of the same specifications and grades to determine whether its conductivity meets the requirements.
IV. Select reliable suppliers
(I) Investigate supplier qualifications and reputation
Prefer suppliers with relevant industry qualification certifications, such as ISO quality management system certification, environmental management system certification, occupational health and safety management system certification, etc. These certifications are a recognition of the supplier's management level and product quality. In addition, attention should be paid to the supplier's business history and market reputation. The supplier's reputation can be understood through Internet searches, industry forums, customer reviews and other channels to check whether there are negative records such as quality disputes, delivery delays, and inadequate services. A supplier with a long operating history and good reputation can usually provide more stable and reliable products and services.
(II) Compare prices and costs
Price is an important factor that cannot be ignored in the procurement process, but the lowest price cannot be the only criterion for selecting suppliers. Too low a price may imply that there is a problem with the quality of the material, or that the supplier uses low-cost, low-quality raw materials and processes in the production process. When comparing prices, factors such as material quality, delivery time, and after-sales service should be considered comprehensively to conduct a comprehensive cost assessment. Suppliers can be asked to provide a detailed quotation list to clarify the composition of various costs, including raw material costs, processing costs, transportation costs, packaging costs, etc., so as to accurately calculate the total cost. At the same time, we negotiate with suppliers for bulk purchase discounts, long-term cooperation discounts, etc. to reduce procurement costs while ensuring quality.
(III) Understand the supplier's production capacity and inventory situation
Ensure that the supplier has sufficient production capacity to meet your procurement needs, especially when large-scale procurement or urgent orders are required. Understand the supplier's production equipment, production process, production scale and production plan arrangements, and determine whether it is capable of providing the required aluminum raw materials on time and in quantity. In addition, the supplier's inventory level is also crucial. Adequate inventory can ensure timely delivery and reduce procurement cycles and risks. You can ask the supplier about the regular inventory varieties, quantities and replenishment cycles so that you can make reasonable arrangements when formulating procurement plans.
(IV) Evaluate after-sales service
High-quality after-sales service can provide you with timely and effective solutions to problems encountered in the use of aluminum raw materials. When choosing a supplier, you should understand whether it provides technical support, such as professional guidance in material processing technology, welding methods, surface treatment, etc.; whether it provides return and exchange services for product quality issues, as well as the process and period for return and exchange; whether it has a complete customer feedback mechanism that can handle customer complaints and suggestions in a timely manner. A supplier who attaches importance to after-sales service can make you feel more at ease and assured during the procurement and use process.
