Study on formability of NbMoTaNiCr refractory high entropy alloy wire arc additive manufacturing

The traditional manufacturing methods for high entropy alloys are generally vacuum arc melting and mechanical alloying, which are limited in forming size. In order to solve the problems in forming and manufacturing of high entropy alloys, an innovative form of wire drawing arc additive was adopted. To explore the influence of TIG arc additive manufacturing process parameters on the formability of NbMoTaNiCr refractory high entropy alloys and improve the forming quality of refractory high entropy alloys, a five factor and five level orthogonal forming experiment was conducted on NbMoTaNiCr refractory high entropy alloys to study the effects of current, electrode spacing, wire feeding speed, stacking speed, and gas flow rate on the forming quality of high entropy alloys. The final research results indicate that the current has the greatest impact on the forming quality of NbMoTaNiCr refractory high entropy alloy. According to the analysis of orthogonal experimental results, it is found that when the current is 120A, the forming quality of NbMoTaNiCr refractory high entropy alloy reaches the optimal level. Meanwhile, it was found that NbMoTaNiCr refractory high entropy alloy is mainly composed of FCC phase and a small amount μ Phase composition. And its average hardness is 911HV. Its compressive yield strength is 545.5MPa, fracture strain is 9.5%, and its fracture mechanism exhibits brittle cleavage fracture.