Effects of Low-Temperature Hot Isostatic Pressing on Tensile Properties of 316L, AlSi10Mg and GRCop42 Alloys Produced by PBF-LB

Powder Bed Fusion–Laser Based (PBF-LB) represents the most-used metal Additive Manufacturing technology thanks to its capability of producing high-complexity geometries. The need for industries to define a qualification framework of additive components drew attention to post-processing approaches that can be applied to mitigate or reduce inherent defects. Among these post-processing approaches, Hot Isostatic Pressing (HIP) is recognized as one of the most effective techniques to address these challenges. Among materials employed with PBF-LB, especially in the aerospace sector, 316L stainless steel and the AlSi10Mg aluminum alloy are the most investigated, while among innovative copper alloys, there is GRCop42. Thus, the aim of this paper is to investigate the effects of low-temperature HIP on the tensile properties and microstructure of these materials. For this reason, tensile tests, metallographic analysis and X-ray computer tomography were conducted. The results highlight the influence of low-temperature HIP treatment with respect to the as-built condition. In particular, the Yield and Ultimate Tensile Strength for 316L and GRCop42 clearly improved, while for AlSi10Mg a relevant reduction was detected. However, an unexpected result was the reduction in the GRCop42 elongation that fell from ~10% down to ~2.5%, even though the porosity of the material was reduced to close to zero.