Ti-17合金高温变形中的不连续屈服与流变软化研究  

Study of Discontinuous Yielding and Flow Softening in High Temperature Deformation of Ti-17 Alloy

作　　者：赖运金[1] 曾卫东[1] 张驰[1] 周建华[2] 王晓英[2] 俞汉清[1] 周义刚[1] 

机构地区：[1]西北工业大学材料学院,西安710072 [2]宝钢股份有限公司特殊钢分公司,上海200940

出　　处：《机械科学与技术》2007年第9期1183-1186,共4页Mechanical Science and Technology for Aerospace Engineering

摘　　要：本文以原始组织为片状的Ti-17合金为例,研究了不连续屈服和流变软化的机理。结果表明:具有片状组织的Ti-17合金在变形温度超过820℃,应变速率为10 s-1时,出现不连续屈服现象,并随着变形温度和应变速率的增大而更加明显,该现象无法用传统的静态理论(位错钉扎-脱钉)进行合理解释,它符合动态理论,即不连续屈服与晶界突然增殖大量可动位错有关。应变速率较高时,具有明显的流变软化特征,其主要是由温升效应和片状组织球化或片层弯折引起的。We study the mechanism of discontinuous yielding and flow softening, taking Ti-17 alloy of lamellar microstructure as an example. The study results show that discontinuous yielding occurs to the alloy when its temperature is above 820℃ and its strain rate is over 10 s^-1. The discontinuous yielding is more apparent asthe temperature and strain rate increase. The explanation of the phenomenon is that it has something to do with the fact that the grain boundary of the alloy suddenly generates a huge quantity of mobile dislocation. The higher the strain rate, the more apparent the flow softening. This is primarily because of temperature-rising effect and the globularization of the lamellar microstructure or lameUae kinking.

关 键 词：TI-17合金 不连续屈服 流变软化 温升效应 球化 

分 类 号：TG146.23[一般工业技术—材料科学与工程]