Low-temperature anomalies of the physico-mechanical characteristics of pseudoamorphous titanium nickelide

Abstract

A study is made of the structure, mechanical properties, and electrical resistance of crystalline and pseudoamorphous (obtained by rolling at 300 K by 50 and 90%) titanium nickelide in both the initial state and after annealing to different temperatures in the interval 513–893 K. It is found that the resistivity of polyamorphous Ti–Ni exceeds 200 μΩ⋅cm, falls off monotonically with increasing annealing temperature, and has a minimum in the low-temperature region 4.2–50 K (Tmin=17–19 K). In the temperature interval 4.2–20 K a nonmonotonic temperature dependence of the ultimate strength of polyamorphous Ti–Ni is observed which increases with increasing degree of deformation by rolling of the investigated material. The results are analyzed. It is conjectured that the observed anomaly of the temperature dependences of the ultimate strength and resistivity are due to low-temperature polyamorphism of the pseudoamorphous Ti-Ni in the temperature interval 10–20 K.