Microstructures and mechanical behaviors of additive manufactured Inconel 625 alloys via selective laser melting and laser engineered net shaping

The microstructure and mechanical behaviors of as-built Inconel 625 prepared by selective laser melting (SLM) and laser engineered net shaping (LENS) technologies were investigated in this study. The results show that the microstructure of Inconel 625 alloy prepared by SLM process is composed of obvious columnar and cellular grains. Inconel 625 fabricated by LENS also has columnar and cellular structures, but the grain size is relatively large. Significant anisotropy of mechanical properties is observed in SLM and LENS printed Inconel 625. The mechanical properties in XY direction are higher than those in XZ direction, and the maximum tensile strength of SLM-XY sample is 1241.5 MPa. SLM printed Inconel 625 has a relatively higher dislocation density of 2.8 ± 1.2 × 1014 m−2. The difference in yield strength between SLM and LENS printed Inconel 625 is mainly caused by the different dislocation strengthening effects.