Combination of hot isostatic pressing and subsequent heat treatment for additively manufactured Zr-1Mo components

Hot isostatic pressing and subsequent heat treatment were performed to achieve defect-free and high-mechanical-performance Zr-1Mo components manufactured by laser powder bed fusion. The strong but brittle acicular α’ martensite phase was observed in the as-fabricated Zr-1Mo components, which transformed into a basketweave α + β microstructure after the HIP process and then transformed into a stress-relieved α phase after subsequent HT. Optical microscopy images and fracture observations revealed that the defects in the as-fabricated components were eliminated after the HIP process and did not regrow during subsequent HT. An ultimate tensile strength of 990 MPa, yield strength of 831 MPa, and elongation of 9.1% were achieved in the heat-treated Zr-1Mo components. The combination of HIP and subsequent HT could be a promising post-processing treatment for L-PBF-fabricated Zr-1Mo components.