Ti8LC合金热变形及其微观组织

Hot Deformation and Microstructure of Ti8LC Alloy

摘要:

采用GLEEBLE-1500热模拟机对Ti8LC合金在温度为850~1000 ℃、变形速率为0.001~0.1 s-1、最大变形程度为60%的条件下，进行恒应变速率高温压缩模拟试验研究，分析合金高温变形时流变应力与应变速率及变形温度之间的关系以及组织变化。结果表明：Ti8LC合金流变应力随应变速率的增大而增大，在恒应变速率条件下，真应力水平随温度的升高而降低；在给定的变形条件下，通过回归计算，建立了一种Ti8LC合金的本构方程；根据试验分析，在850~950 ℃温度时变形，主要发生动态再结晶，随着温度的升高，软化机制主要是动态回复。

Abstract:

High temperature compression simulation tests were carried out on Ti8LC alloy at a constant strain rate by a GLEEBLE-1500 thermal simulator, under the conditions of 850-1000 oC, 0.001-0.1 s-1 and maximal deformation of 60%. The effects of the strain rate and the forming temperature on the flow stress and the microstructure transition were investigated. The results reveal that the flow stress of Ti8LC increased as the strain rate increased, and at a constant strain rate the true stress decreased as the forming temperature increased. In the situation of experiment, the constitution equation of Ti8LC alloy was established by regression calculation. According to the experimental analysis, dynamic recrystallization happened while deformed at 850-950 oC. In addition the dynamic recovery was the mainly softening mechanism at evaluated temperature.