On the role of Zr and B addition on solidification cracking of IN738LC produced by laser powder bed fusion

The demand for manufacturing increasingly complex geometries high temperature applications drives the increasing interest into additive of nickel-based superalloys. Of particular are superalloys with contents strengthening phase ?' such as IN738LC. Previous research suggests that especially B and Zr have a detrimental influence on crack formation during laser powder bed fusion (LPBF) process. present study investigates solidification cracks in an IN738LC derivative increased (0.03 wt.%) (0.07 more detail using resolution techniques transmission electron microscopy (TEM) atom probe tomography (APT). Analysis bulk material shows number MC carbides containing Ti Cr. concentration profiles indicate non-equilibrium carbide compositions by suggesting Cr is pushed out these particles. surrounded thin B-rich layer at metal/carbide interface. fracture surface both small amounts formed oxide layer. presence elements together thermodynamic calculations previously reported findings same variant support hypothesis low-melting phases likely reasons cracking