Synthesis of Powder Alloys Based on the Ti–Ni–Hf System via a Calcium Hydride Reduction Process

We have demonstrated the feasibility of preparing powder alloys based on intermetallic phases in the Ti–Ni–Hf and Ti–Ni–Hf–Zr systems by a calcium hydride reduction process and investigated the physicochemical and technological properties of Ti40Ni50Hf10, Ti28Ni50Hf22, and Ti28Ni50Hf12Zr10 powders thus prepared. Experimental data show that the synthesis of the powders typically involves the formation of intermediate phases inherent in the binary phase diagrams of the constituent components of the alloys. According to X-ray diffraction data, the synthesized powders consist predominantly of B19' martensite, whose content depends significantly on the synthesis temperature. At given process parameters, the alloy with the lowest Hf dopant concentration is the most homogeneous.