Laser metal deposition of Inconel 625: Microstructure and mechanical properties

Laser metal deposition (LMD) is used in industry to coat, additive manufacture, and/or repair high value metal components through deposition and laser induced melting of powder delivered in a gas stream. This study relates to the production of three-dimensional Inconel 625 components by LMD. After LMD, a dense cellular – dendritic structure containing carbides of the type MC, M23C6, and M6C has been detected by x-ray diffraction. Parts with tensile yield strengths, ultimate strengths, and elongations in the range of, respectively, 480–656 MPa, 882–1000 MPa, and 24%–36% have been obtained. Compression testing along and perpendicular to the build direction reveals a slight anisotropy in fracture strength. This is attributed to the preferential orientation of the dendrites parallel to the build direction. Tensile test samples have been fabricated in “lying” and “standing” orientations. The tensile yield and ultimate strength are considerably lower and the elongation is larger for the samples built in standin...