Fabrication of Crack-Free Nickel-Based Superalloy Considered Non-Weldable During Laser Powder Bed Fusion

Materials (Basel). 2018 Jul 25;11(8):1288. doi: 10.3390/ma11081288.

Abstract

Crack-free Hastelloy X fabricated through laser powder bed fusion (LPBF) from powder with a standard chemical composition is reported. Electron backscatter diffraction (EBSD) analysis evidenced columnar grains parallel to the building direction. The typical LPBF columnar dendrite microstructure was found to be finer than reported elsewhere. Mo-enriched carbides (~50 nm), presumed to play an important role in the cracking behavior of the alloy, were confirmed along interdendritic regions. Crack-free condition was maintained after heat treatment at 1177 °C for 1 h followed by water quenching, and the resulting microstructure was analyzed.

Keywords: Hastelloy X alloy; additive manufacturing; laser powder bed fusion (LPBF); microstructure; nickel alloys; scanning electron microscopy (SEM).