摘要
在温度940～1000℃、应变速率10-2～50s-1、最大变形程度50%条件下利用Gleeble-1500型热模拟试验机对Ti-22Al-25Nb合金的高温流动应力变化规律进行了研究,分析了热变形参数对流动应力的影响规律,并利用Zener-Hollomon参数建立了该合金的本构关系。试验结果表明,应变速率的降低或温度的升高都会使合金的流动应力降低;变形过程中产生的流动软化现象与温升效应和组织变化有关;高应变速率(≥10s-1)条件下发生的应力不连续屈服现象与晶界突然增殖大量可动位错有关,与固溶原子的钉扎无关。
The hot compressive deformation test of Ti-22A1-25Nb alloy was performed on Gleeble- 1500 hot simulator in the range of deformation temperature from 940℃ to 1000℃, strain rate from 10^-2 s^-1 to 50s^-1, maximum deformation degree 50%. The effect ofhot-deformatim parameters on flow stress was analyzed. A constitutive relationship of this alloy described by Zener-Hollomon parameter was formulated.The result shows that the flow stress of the alloy decreases with the swain rate decreasing or the temperature increasing.The flow softening extensively is attributed to temperature rising and microstructurel changes of this alloy. Discontintious yielding which occurred at higher swain rate （ ≥ 10s^-1） is associated with the generation of new mobile dislocation from grain boundary sources, but independent of solute-pinning.
出处
《热加工工艺》
CSCD
北大核心
2007年第1期1-4,共4页
Hot Working Technology
基金
西北工业大学本科重点扶持项目(2006018)
