Study on Microstructure and Properties of Inconel 625 Alloy Fabricated by CMT - Based Wire and Arc Additive Manufacturing

Abstract

In order to provide a simple and feasible method for the efficient and high-quality forming of large and complex nickel-based Inconel 625 alloy parts,Inconel 625 alloy samples were prepared by CMT-based wire and arc additive manufacturing method.The microstructure,mechanical properties,corrosion resistance and anisotropy of the samples were investigated.Results showed that the main phase of the samples was γ Ni solid solution with FCC structure,the precipitation phases were mainly Laves phase and MC type carbide,and most of the microstructures were dendrites growing along the height direction.In addition,the hardness and tensile strength were anisotropic,and the samples possessed a hardness of 257～308 HV5 N,a tensile strength of 690～750 MPa,a yield strength of 460～550 MPa,and an elongation of 34%～40%.The tensile strength of the alloy in x and z directions at room temperature reached the standard of forged ones of the same grade,the fractures were all typical ductile fractures,and there were Laves phase and a small amount of second phase particles of carbides in the fracture dimples.Besides,the effect of anisotropy on corrosion performance was not obvious,and the corrosion resistance along stacking direction was slightly better than that along the other two directions.

Keywords

• cmt wire and ar|additive manufacturin|inconel 625 alloy|anisotropy|mechanical property