摘要
研究了AZ31镁合金在150～250℃、等效应变速率0.001～0.25 s-1内一道次等温等径角变形(ECAP)过程中的变形与断裂行为。剪切带和剪切断裂的观察结果可由量化应力集中趋势的局部流变集中参数α来预测。结果表明,AZ31镁合金在ECAP变形过程中极易发生局部剪切,而均匀变形只发生在高温和低应变率条件下;通过材料性能对局部流变趋势的影响,可选择最优的加工方案,以获得材料的均匀变形。
The deformation and fracture characteristics of AZ31 alloy during equal channel angular pressing （ECAP） were investigated at temperatures between 150℃ and 250 ℃ and ram speeds producing average effective strain rates between 0.001 s-1 and 0.25 s-1. Observations of shear banding and shear fracture were interpreted in terms of the tendency for strain concentration as quantified by the flow localization ＇c~ ＇ parameter, or the ratio of the normalized flow softening rate to the strain-rate sensitivity. The results show that AZ31 alloy is particularly susceptible to shear localization during ECAP; the uniform flow occurs only at high temperatures and low strain rates. These conclusions of the effects of material properties on flow localization tendency are helpful for the selection of optimum processing parameters, and then the uniform deformation can be obtained during ECAP.
出处
《热加工工艺》
CSCD
北大核心
2012年第8期81-85,共5页
Hot Working Technology
关键词
等径角变形
AZ31镁合金
剪切断裂
局部流变
equal channel angular pressing
AZ31 alloy
shear fracture
flow localization
