Effects of Hot Isostatic Pressing on Mechanical Property and Thermal Conductivity of Laser Powder Bed Fusion (LPBF) AlSi10Mg Alloy

This paper systematically studies the influence mechanism of hot isostatic pressing (HIP) on the microstructure and properties of AlSi10Mg alloy fabricated by laser powder bed fusion (LPBF). The results reveal that HIP treatment transforms the original fine-grained microstructure and eutectic Si skeleton into coarsened α-Al matrix with granular Mg₂Si precipitates, leading to significant decrease in tensile strength from 487 MPa to approximately 150 MPa, while, toughness has been enhanced. Concurrently, the thermal conductivity of alloy is significantly improved, with the thermal conductivity increasing from 99 W/(m·K) to a maximum of 148 W/(m·K). These property variations originate from microstructural evolution: the elimination of the eutectic Si skeleton, reduction of porosity, and grain coarsening, collectively diminish the resistance to free electron movement, thus, improving thermal conductivity, but also resulting in reduction of substantial strength. This research provides insights for exploring different heat treatment routes to achieve a beneficial balance between mechanical and thermal properties, comprehensively enhancing overall performance of heat-dissipation components.