Effect of ultrasonic deformation on nickel at low temperatures

A technique is described for ultrasonic deformation of metals at helium temperatures. A study is made of the temperature dependence of ultrasonic hardening (on the basis of the microhardness) and of the electrical resistivity in nickel. It is established from the results of investigations on the recovery of resistivity that a wide range of defects is formed during ultrasonic deformation of nickel in liquid helium.