The Role of Aluminum-silicon Alloy Powder in Additive Manufacturing

Additive Manufacturing and the Rise of Aluminum Alloy Powder

The global aluminum-silicon alloy powder industry experiences rapid growth because lightweighting requirements in both automotive and medical applications drive market expansion. The automotive industry achieves vehicle weight reduction and improved energy efficiency through aluminum alloy parts while the medical field manufactures biocompatible customized implant devices.

The AlSi₁₀Mg aluminum alloy stands as the fundamental material for additive manufacturing technology because of its lightweight nature (density 2.67-2.68 g/cm³), excellent strength-to-weight ratio (430 MPa tensile strength and 270 MPa yield strength) and its superior thermal conductivity (130-190 W/m·K). The material maintains performance consistency through its strict chemical composition control of 9-11% silicon and 0.2-0.45% magnesium and finds extensive use in automotive chassis and medical implants applications.

Alloy Powders Products List

• High-Temperature Alloy Powders
• Stainless Steel Powders
• Precision Alloy Powders
• High-Entropy Alloy Powders
• Other Alloy Powders

Material Properties and Standardization of AlSi₁₀Mg Powder

Chemical composition and physical properties: AlSi₁₀Mg is based on aluminum, with silicon (9-11%) and magnesium (0.2-0.45%) as the main alloying elements, and the total amount of impurities (such as iron and manganese) does not exceed 0.55%. The addition of silicon improves casting fluidity and mechanical strength, while magnesium further strengthens the alloy through precipitation hardening. High sphericity (sphericity ≥ 96%), particle size range 15-53 microns (mainstream standard is 15-45 microns), excellent fluidity (<70 seconds/50g). Density is about 2.67-2.68 g/cm³, melting point is about 615°C, suitable for processes such as laser selective melting (SLM).

Performance advantages: After SLM forming, the tensile strength reaches 360-460 MPa and the elongation is 8-10%, which is better than traditional cast aluminum alloys.

The oxide layer formed by silicon can resist corrosion in neutral water environment, but is sensitive to salt spray environment. Spherical particles and high fluidity ensure uniform powder spreading, reduce printing defects, and achieve a density of more than 99.95%.

Application of AlSi₁₀Mg in Additive Manufacturing

Automotive industry

AlSi₁₀Mg has outstanding performance in the field of lightweight automobiles. For example, for crack repair of 2A14 aluminum alloy wheel hub, by optimizing parameters such as laser power (2800 W), scanning speed (480 mm/min), and single layer thickness (0.5 mm), the surface of the repaired wheel hub is smooth and dense, without pores and crack defects. During the repair process, AlSi₁₀Mg has good interface bonding with the matrix, and the microstructure presents a continuous network distribution of eutectic Si phase and α-Al matrix phase, with a tensile strength of 370 MPa and an elongation of 6.4%, which fully meets the use requirements. The experiment also verified the defect-free metallurgical bonding between the repair area and the matrix through SEM images.

Medical and consumer electronics

The biocompatibility of AlSi₁₀Mg makes it an ideal choice for medical implants, such as orthopedic prostheses and surgical instruments. Its thin-walled complex structure manufacturing capability is also favored in the consumer electronics field, such as the production of high-precision heat sinks and micro-housings. Through selective laser melting (SLM) technology, AlSi₁₀Mg can form complex parts with a surface roughness of Ra6.3 μm and a dimensional accuracy of ±0.2 mm, and its mechanical properties far exceed those of traditional castings.

Technical Challenges and Solutions

Process Difficulties: Rapid cooling leads to large temperature gradients and easy generation of pores. Low scanning speeds are prone to metallurgical pores, while high speeds lead to unfusion. Solutions include substrate preheating (reducing cooling rate), multiple remelting (reducing porosity) and optimizing laser energy density (such as 2800 W power + 480 mm/min speed combination). Non-spherical particles or wide particle size distribution (such as insufficient proportion of powder below 50 μm) will affect the uniformity of powder spreading. Improving the sphericity of powder through plasma atomization technology and strictly screening the particle size (such as 15–53 μm range) can significantly improve the printing quality.

Cost and Sustainability: The high cost of AlSi₁₀Mg powder restricts large-scale application. Recycling waste powder can reduce costs and be used to produce by-products such as foaming agents to achieve a circular economy.

Future Trends and Innovation Directions

Develop new alloys such as Al-Cu and Al-Zn to reduce oxidation problems, or optimize performance through mixed powders (such as 316L stainless steel). For example, adding beryllium (Be) and erbium (Er) to Al-Si-Mg alloys can increase density to 99.96%.

Plasma atomization technology can improve the sphericity of powders, and the powder particle size distribution is more concentrated after the gas atomization pressure is optimized. Use topology optimization software to accelerate the design of complex structures, and combine LPBF/DED hybrid technology to achieve high-performance component manufacturing.

The entry of new manufacturers promotes large-scale production, and the cost of powder is expected to be further reduced. At the same time, the improvement of the standardized certification system will promote applications in high-end fields such as medical care.