Processing, microstructure, and mechanical properties of additive manufacturing Inconel 625 using hot wire laser metal deposition

Inconel 625 alloy components were fabricated using hot wire laser metal deposition (HW-LMD) through process optimization, achieving a wire deposition rate of 1.72 kg/h. The microstructure and mechanical properties of the HW-LMD Inconel 625 alloys were systematically investigated. The results revealed that the microstructure of the HW-LMD Inconel 625 alloys consisted of columnar dendrites, characterized by an average grain size of 12.5 µm and a strong {100}〈001〉 texture. The main phase identified was γ -Ni, with the precipitation of Laves phase, measuring less than 1 μm, observed in the inter-columnar dendritic regions. The average microhardness of the HW-LMD Inconel 625 alloys was HV 1.0 258. The yield strength and ultimate tensile strength were 493.5 and 837.4 MPa, respectively, with elongation exceeding 50%. Impact absorbing energies at 25 and −78 °C were 223.08 and 200.24 J, respectively. Both the tensile and impact fracture surfaces exhibited dimples, indicating a ductile fracture mechanism during the deformation process.