응력이완 시험을 이용한 고순도 Sn 의 변형거동 연구 = A Load Relaxation Study on Deformation Behavior of a Pure Tin

다국어 초록 (Multilingual Abstract)

The objective of this study is to demonstrate that the white tin exhibits the behavior of mechanical equation of state for plastic deformation at room temperature, as was first suggested by Hart. The existence of the mechanical equation of state can be verified by a scaling relation of stress-strain rate curves obtained at various plastic strain levels for a particular material. Variety of metals and alloys with cubic structure have been reported to show the behavior of mechanical equation of state. In this study, an explicit form of mechanical equation of state for plastic deformation has been provided based on the internal variable theory of inelastic deformation, recently proposed and verified by the scaling of stress vs. strain rate curves obtained from a series of load relaxation tests. The principal advantage of load relaxation test is to provide a broad range of strain rates with a minimal plastic straining, so that the flow behavior can be obtained without changing the internal structure appreciably. The effect of temperature on the flow behavior of pure tin has also been investigated by conducting load relaxation tests at various temperatures. The activation energy for plastic deformation in pure tin at the temperature range from room temperature to 140℃ was obtained as 46.4kJ/mole, which is very similar to that for grain boundary self diffusion.