液体ヘリウム中での金属材料の引張挙動におよぼす歪み速度の影響

Abstract

Tensile test was carried out on four alloys at liqud helium temperature to study the effect of strain rate on the deformation behavior. Alloys used were Fe-13%Ni alloys, SUS 304L, SUS 310S and 5083-O aluminum alloys, which were fully ductile even at liquid helium temperature.At lower strain rate serrated flow was observed for every alloy, and at higher rate all flow curves became smooth. Proof stress has little strain rate dependence, but tensile stress decreases with an increase in strain rate. The latter fact would be associated with adiabatic deformation, which depends upon the thermal properties of the alloys at low temperatures.