Fatigue Properties of Inconel 625 Alloy Parts Manufactured by Wire Arc Additive Manufacturing Method

In the present study, Inconel 625 alloy walls were fabricated by wire arc additive manufacturing method. Microstructure, hardness, tensile properties at room temperature and 700 ˚C, and high-cycle fatigue strength in both welding and building directions of samples were evaluated. The microstructure of the wall contained dendritic Ni-based solid solution along with MC carbide, Laves, and delta inter-dendritic phases. Moreover, the Vickers hardness value decreased from 380 HV near the substrate to 300 HV in the top layer. Also, yield and tensile strengths along the welding direction were 6.6 and 8.6% higher and the elongation was 23% lower than the building direction, respectively. Furthermore, fatigue test results with the stress ratio of 0.1 showed that the number of cycles to failure was slightly higher in the welding direction. Fractography of the samples illustrated that all fatigue cracks initiated from the surface. This confirmed the soundness of the walls manufactured by this method.