Production of AlSi10Mg alloy materials: SLM technology and cryogenic treatment

Abstract

Aluminum alloys have recently gained significant importance in the industry due to their increasing use in various applications. Among them, AlSi10Mg alloys are especially utilized in the automotive, aerospace, and defense sectors, where the need to balance low weight with desirable thermal and mechanical properties is critical. The rapid advancement of additive manufacturing (AM) technologies has further driven research efforts to develop new alloys that are both environmentally sustainable and economically viable. Selective Laser Melting (SLM), a key AM technology, is particularly advantageous for producing complex components, as it enables the creation of lightweight parts with optimized topology. Despite these advantages, post-processing requirements remain a challenge in AM. Cryogenic treatment, which has shown promising effects on AlSi10Mg parts, is sometimes chosen even when specialized heat treatments are needed. This study examined the mechanical properties of AlSi10Mg alloy produced using SLM. The blocks were manufactured using a stripe scan strategy with 700W laser power, dual laser, and a 60 µm layer thickness. After production, samples were extracted from these blocks and subjected to cryogenic treatment in cycles of 24 and 36 hours at -196°C. Following the cryogenic treatment, tensile and hardness tests were conducted to investigate the mechanical properties. The results indicated that the hardness of the cryogenically treated samples improved over their as-built state after a 36-hour cycle, but decreased after a 24-hour cycle. While there were no significant differences in hardness based on the length of the cryogenic treatment, the percent elongation values increased with longer treatment cycles. However, tensile and yield strength values were higher in samples treated for 24 hours, with a slight decrease observed in those treated for 36 hours. In conclusion, although the cryogenic process did not significantly alter the hardness of the SLM AlSi10Mg samples, it had a notable impact on their tensile strength, yield strength, and percent elongation values.