발간논문

Home > KJMM 논문 > 발간논문

Vol.31, No.1, 48 ~ 58, 1993
Title
High temperature Deformation Behavior of 7475 Al Alloy
성환진Hwan Jin Sung, 김기수Ki Soo Kim, 장영원Young Won Chang
Abstract
The purpose of present study is to establish a new inelastic deformation theory based on dislocation mechanisms and grain boundary sliding applicable at high temperature. The basic concept of this theory is that the grain boundary sliding accomodated by grain matrix deformation plays a major role in the large superplastic deformation. Expanding the unified internal variable theory of inelastic deformation, new constitutive parameters and mechanical equation of state for grain boundary sliding are proposed from the consideration of dislocation kinetics. A series of load relaxation tests were then conducted to verify for the existence of mechanical equations of state for 7475 Al alloy. The stress-strain rate curves obtained from the load relaxation tests of 7475 Al alloy were found to fit well to the proposed state equations. The combined effect of temperature and grain size on the behavior of grain boundary sliding is also shown to be well characterized by the two structural parameters ∑_g and σ in the proposed state equations. A modification of the Hall-Petch equation is also suggested to replace the flow stress σ by σ. Finally, the conventional strain rate sensitivity parameter should also be replaced by new parameters defined by the internal state variables.
Key Words
| PDF
대한금속∙재료학회 │ (06633) 서울시 서초구 서초대로 56길 38 대한금속∙재료학회 회관 (서초1동 1666-12번지)
Tel : 070-4266-1646 │ FAX : 02-557-1080 │ E-mail : metal@kim.or.kr
Copyright ⓒ 2013 사단법인 대한금속∙재료학회 All rights reserved.