Aluminum alloys Metal Parts Processing

Characteristics and Advantages of Aluminum Metal

• Low Density: Aluminum has a relatively low density, approximately 2.7g/cm³, which makes the parts made from aluminum relatively lightweight. For example, in the aerospace field, the use of aluminum parts helps reduce the weight of aircraft, thereby reducing energy consumption and increasing the payload. Parts such as the wing structures and fuselage frames of airplanes often use aluminum components.
• Good Electrical Conductivity: Aluminum has good electrical conductivity and is widely used in the manufacturing of electrical equipment. For instance, some connection parts of wires and cables and certain conductive structures inside distribution boxes can be made into parts that meet the requirements of electrical conduction by processing aluminum metal.
• High Thermal Conductivity: It has excellent thermal conductivity, so it is often used to manufacture parts that require heat dissipation. For example, the heat sinks of computers and the heat dissipation parts of automobile engines can quickly conduct heat out to ensure the normal operation of the equipment.
• Easy to Process and Form: Aluminum metal is relatively soft and has good plasticity. It can be processed into various parts with complex shapes through multiple processing techniques. For example, through extrusion, forging, cutting and other processes, aluminum parts for different purposes can be manufactured.
• Corrosion Resistance: A dense aluminum oxide protective film is easily formed on the surface of aluminum, which enables it to resist the corrosion of the external environment to some extent. For example, some outdoor aluminum railings and aluminum building decoration components can maintain their appearance and performance stability for a long time after processing.

Common Processing Techniques

• Cutting Machining:
  • Turning: Using a lathe, the aluminum metal bar stock is fixed on the chuck, and through the rotary cutting of the cutting tool, parts with a rotary body shape can be processed, such as aluminum shaft parts and bolts. The dimensional accuracy of the outer diameter, inner diameter and length can be precisely controlled.
  • Milling: By using a milling machine, the cutting tool rotates at high speed to mill the aluminum metal blank fixed on the workbench, and planes, grooves, various contour shapes and so on can be processed. For example, when processing the cavity of an aluminum mold or the installation plane of a mechanical part, different shapes of milling cutters and reasonable cutting parameters can be selected to achieve diversified shape processing.
  • Drilling: With the help of a drill bit on a drill press or a machining center, holes of various diameters can be drilled in aluminum metal materials. For example, holes are drilled in aluminum plates for assembly and connection, or holes for installing shaft parts are drilled in box-shaped parts. Ensuring the positional accuracy of the holes and the accuracy of the hole diameter is crucial.
• Forging: By applying pressure to the aluminum metal blank, it is made to undergo plastic deformation to obtain the required shape of the part. Forging can refine the metal structure and improve the strength and toughness of the part. It is often used to manufacture aluminum parts with high requirements for mechanical properties, such as aluminum alloy wheels of automobiles and some key stressed parts of aero-engines. Generally, it is divided into different methods such as free forging and die forging. Die forging can more accurately control the shape and dimensional accuracy of the part.
• Extrusion: The heated aluminum metal blank is put into the extrusion cylinder, and pressure is applied through the extrusion rod to make the metal extrude from the die hole with a specific shape, thus forming profiles with continuous cross-sectional shapes. For example, common aluminum profiles for doors and windows and various industrial aluminum track profiles are produced by the extrusion process. This process has high production efficiency and is suitable for mass-producing long-strip parts with regular shapes.
• Casting:
  • Sand Casting: First, a sand mold is made, and then the molten aluminum metal liquid is poured into the mold cavity. After cooling and solidification, the part with the required shape is obtained. This method has relatively low cost and is suitable for manufacturing aluminum parts with complex shapes and large sizes, such as the shells and bases of some machinery. However, the dimensional accuracy and surface quality of the castings are relatively limited.
  • Die Casting: Using a metal die-casting mold, the aluminum metal liquid is quickly injected into the mold cavity under high pressure. After cooling, high-precision and good-surface-quality parts are obtained. It is often used to manufacture the cylinder blocks of automobile engines and the aluminum alloy shells of mobile phones and other electronic products. It has high production efficiency, but the mold cost is relatively high and it is suitable for mass production.

Key Points of Quality Control

• Control of Dimensional Accuracy: During the processing process, it is necessary to strictly follow the requirements of the design drawings. The dimensions of aluminum parts should be detected by precise measuring tools (such as calipers, micrometers, coordinate measuring machines, etc.) to ensure that the dimensional deviations are within the allowable tolerance range. This is crucial for the assembly and performance of the parts.
• Control of Surface Quality: Attention should be paid to the surface roughness of the parts, as well as whether there are scratches, pores, cracks and other defects. Appropriate processing parameters, cutting tools and necessary surface treatments (such as grinding, polishing, anodizing, etc.) should be adopted to improve the surface quality. For example, for the aluminum shells of electronic products with high appearance requirements, the surface needs to be smooth and free of flaws.
• Guarantee of Mechanical Properties: According to the usage requirements of the parts, it is necessary to ensure that they have corresponding mechanical properties such as strength, hardness and toughness. This can be achieved by reasonably selecting the aluminum alloy grade (different aluminum alloys have different compositions and mechanical properties), processing techniques (such as forging can improve strength) and carrying out necessary heat treatment. For example, the key stressed aluminum parts in the aerospace field need to undergo strict mechanical property tests to ensure their reliability.

Application Areas

• Aerospace Field: Besides reducing weight and meeting certain mechanical property requirements mentioned above, aluminum metal parts are also used for satellite structural parts, the outer shells of rocket fuel tanks and so on in this field to meet various performance requirements in the space environment.
• Automotive Industry: From some aluminum structures of the body frame to aluminum alloy decorative parts in the interior, and then to aluminum parts in key systems such as engines and transmissions, a large number of aluminum metal processed parts are widely used in automobiles, which helps to realize the lightweight of automobiles and improve fuel economy and handling performance.
• Electronics and Electrical Appliances Industry: Many electronic products rely on aluminum metal parts. For example, the shells of laptops, the frames of smartphones and the heat dissipation structures of televisions not only meet the requirements of appearance design but also conform to the functional usage requirements.
• Construction Industry: Decorative aluminum panels on the exterior facades of buildings, aluminum profiles for doors and windows, aluminum ceilings indoors, etc. Through processing aluminum metal, they have the characteristics of beauty, durability and easy installation and are widely used in various construction projects.