Powder metallurgical processing of ternary Ni50Ti50−xZrx (x = 5, 10 at.%) alloys

Almost single-phase ternary Ni50Ti50−xZrx alloys with x = 5 and 10 at.% zirconium nominal contents have been successfully produced using the alternative powder metallurgical VPCR process. This process, based on the solid-state sintering of Ni, TiH2 and ZrH2 powder mixtures under highly reducing atmosphere (Ca reducing vapor), prevents efficiently the complex oxide formations. Furthermore, the produced Ni50Ti50−xZrx alloys do not show the well-known secondary intermetallic phases belonging to the binary Ni-Ti and Ni-Zr systems as well as to the ternary Ni-Ti-Zr system. X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray (SEM/EDS) analyses show that the chemical homogeneity of the produced NiTiZr alloys was similar to that of corresponding melt-cast alloys but some residual porosity was still present.