High Pressure Heat Treatment of AM parts - Combining HIP and Heat treatment

Hot Isostatic Pressing (HIP) plays an important role for metal additive manufacturing to assure and increase the quality and mechanical performance of the produced components by eliminating internal porosity in the material. Traditionally HIP:ing has been used only to eliminate defects in the material and modification and optimization of the microstructure is performed in conventional heat treatment processes after the HIP step. As a results of the development in HIP equipment it is now possible to do high pressure gas quenching in the HIP furnace with cooling rates up to 8000 F/min at up to 30 000 psi (2070 bar). This technology makes it possible to combine the HIP step with conventional heat treatments into one cycle in the HIP with the main purpose to reduce the number of process steps. This presentation will show studies of combined HIP and heat treatment for different alloys and how it can improve the microstructure and material properties of components. It has been shown that the high pressure during heat treatment in HIP can have an influence on the thermodynamics and thus the heat treatment response and this will also be discussed.