Effect of hot isostatic pressing temperature on microstructures and characteristics of AlSi10Mg alloy fabricated by selective laser melting

AlSi10Mg alloys produced by the Selective Laser Melting (SLM) process experience significant issues due to rapid cooling, necessitating post-processing. Direct Hot Isostatic Pressing (HIP), which applies high-temperature isostatic pressure, has emerged as a promising solution to mitigate these problems. This study investigates the effects of various Direct HIP temperature conditions on the properties of AlSi10Mg alloys produced by SLM. The results showed that internal pores were completely eliminated at temperatures of 400 °C or higher, while residual stress was significantly relieved at 200 °C or higher. Furthermore, increasing the HIP process temperature promoted Si precipitation, resulted in the breakdown of the Si network structure, and led to the coarsening of precipitates This resulted in a trade-off phenomenon, where mechanical properties deteriorated while thermal and electrical conductivity improved. In conclusion, although the HIP process effectively healing internal porosity at 400 °C, it also led to a significant reduction in mechanical properties.