摘要
利用Hopkinson压杆进行动态冲击压缩试验,测试了不同应变速率下Mg-8%Li合金的动态应力-应变曲线;分析了Mg-8%Li合金动态应力-应变行为的应变速率效应及其变形局部化现象与形成条件。结果表明,Mg-8%Li合金的动态应力-应变曲线随应变速率提高而先升高后降低,即Mg-8%Li合金的应力-应变行为由正应变速率效应向负应变速率效应转化,其应变速率效应转折点与显微组织中出现的变形局部化现象有密切关系,而且该合金在应变速率提高(3700/s→4600/s)后,产生变形局部化需要的应变下降(0.28→0.185),表明Mg-8%Li合金要形成变形带,必须使材料在一定的应变速率下获得相应的应变。
The dynamic impact compression experiments for Mg-8% Li alloy were carried out using the Hopkinson pressure bar. The dynamic stress-strain curves of the alloy at the different strain rate were tested, and the strain-rate effects, the phenomenon of deformation localized and it＇s forming conditions were analyzed. The results showed that dynamic stress-strain curve of the alloy increased at first and then decreased with the strain rate increasing. That was to say, the behavior of stress-strain presented the positive effects and the negative effects of strain rate. The turning point of the strain rate effect had close relationship with the phenome-non of the deformation localized in the alloy. The strain that the local deformation needed decreased （0.28→0.185） while the strain rate increased（3 700/s→4 600/s） .This result revealed that deformation band in Mg-8% Li alloy may form when the strain in the alloy got the certain value under corresponding strain rate.
出处
《轻合金加工技术》
CAS
北大核心
2009年第4期50-53,共4页
Light Alloy Fabrication Technology
