Synthesis of the Ti-Zr-Ni alloys by the "hydride cycle" method

A comprehensive study of the technical parameters and conditions for the synthesis of ternary alloys in the Ti-Zr-Ni system by the "hydride cycle" method was carried out. The influence on the synthesis process of such parameters as: temperature and annealing time, heating rate, cooling conditions, material composition, dispersion, hydrogen content in the hydrides used, the presence of impurities, mixing and pressing methods, and the degree of pressing of the starting components was determined. The alloys of the following compositions were synthesized and investigated: Ti_40.5Zr_31.9Ni_27.6, Ti_41.5Zr_41.5Ni₁₇, Ti₄₀Zr₄₀Ni₂₀, Ti₄₄Zr₄₀Ni₁₆. The optimal technological parameters and conditions for the synthesis of ternary alloys are determined. It has been established that the key factors in the process of compound formation during hydride dissociation are the dispersion and homogeneity of the initial compacted components. It was found that the synthesis of ternary alloys in the Ti-Zr-Ni system occurs during a short-term exothermic reaction in the "thermal explosion" mode, which begins in the temperature region corresponding to the α↔β polymorphic transformation of zirconium and titanium. (author)