Mg-8% Li合金的拉伸变形行为及其应变率效应  

Tensile deformation behavior and its dependence on strain rate of Mg-8% Li alloy

作　　者：于涛[1] 王洪顺[1] 沙桂英[1] 石继红[1] 杨林[1] 

机构地区：[1]沈阳航空航天大学材料科学与工程学院,辽宁沈阳110036

出　　处：《轻合金加工技术》2010年第11期55-58,共4页Light Alloy Fabrication Technology

基　　金：航空科学基金(04G54009)

摘　　要：利用电子拉伸试验机在不同拉伸速率下对具有密排六方结构(HCP)和体心立方结构(BCC)的双相Mg-8%Li合金进行了拉伸试验。结果表明,在0.05 mm/min和0.5 mm/min拉伸速率下,该合金产生了塑性不稳定现象(PLC效应);在0.05 mm/min～50 mm/min拉伸速率范围内,随着拉伸应变率的增加,合金产生了显著的正应变率效应。微观断裂机制主要是微孔聚合型韧性断裂,但随着应变率提高,合金断口表现出一定的脆化倾向。The tensile tests were carried out for Mg-8 % Li alloy with two-phase structure of HCP and BCC lattice under different tensile rates by electronic tensile test machine. Results indicated that the PLC effect occurred during tensile deformation of Mg-8 % Li alloy in strain rate of 0.05 mm/min - 0.5 mm/min. And tensile properties of the alloy showed positive strain rate effect caused by strain rate strengthening with increasing strain rate in rate range of 0.05 mm/min- 50 mm/min. The fracture micro-mechanism of the alloy represented ductile fracture with polymerized mini-apertures in the fracture surface, and fractography of the alloy indicated brittle fracture tendency with increasing strain rate.

关 键 词：MG-LI合金 应变率 PLC效应 韧性断裂 

分 类 号：TG146.22[一般工业技术—材料科学与工程]