添加Y对Mg-3.5%Li合金冲击变形行为的影响  

Effect of Y Addition on Impact Deformation Behavior of Mg-3.5%Li Alloy

作　　者：沙桂英[1] 刘翠云[1] 刘腾[1] 孙晓光[1] 李根[1] 

机构地区：[1]沈阳航空工业学院材料科学与工程学院,沈阳110136

出　　处：《材料工程》2010年第7期64-67,共4页Journal of Materials Engineering

基　　金：国家自然科学基金(50801048);航空科学基金(04G54009)

摘　　要：利用Hopkinson压杆技术对Mg-3.5%Li及Mg-3.5%Li-0.77%Y合金在不同应变率下进行了冲击压缩实验,分析了两种合金的动态应力-应变行为及其应变率效应。结果表明,随应变率提高,Mg-3.5%Li合金的应力-应变行为表现出应变率强化效应与应变率弱化效应的双重特性。添加稀土元素Y后,合金有所强化,但其应力-应变行为仍具有应变率弱化效应,随应变率提高产生的微裂纹引起的内部损伤是导致合金应变率弱化效应的主要原因。The impact compression experiments for Mg-3.5%Li alloy and Mg-3.5%Li-0.77%Y alloy were carried out at different strain rates with the Split Hopkinson Pressure Bar.The dynamic stress-strain behavior and strain rate effect of the alloys were analyzed.Results showed that dynamic stress-strain curves of the Mg-3.5%Li alloy exhibited positive and subsequent negative strain rate effect with the increase of strain rates.The alloy was strengthened by the addition of Y,but the dynamic stress-strain behavior of the alloy still exhibits negative strain rate effect.This behavior was attributed to inner damage of the Mg-3.5%Li-0.77%Y alloy caused by the micro-crack with the increase of strain rates.

关 键 词：MG-LI合金 Mg-Li-Y合金 应变率 微裂纹 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]