摘要
采用不同轧制退火工艺处理AZ31变形镁合金,采用分离式Hopkinson压杆测试了不同微观组织镁合金的动态力学性能,研究了组织结构与材料动态力学响应之间的关系,探讨了应变率效应。研究发现,分别经过5%,30%第三道次轧制以及250,350℃退火处理的镁合金晶粒尺寸差异较大。在应变率范围为1.2×103~2.4×103/s范围内,具有不同晶粒尺度的AZ31镁合金表现出各异的应变率强化效应。根据动态应力-应变曲线拟合了与动态屈服强度和动态抗压强度相对应的应变率硬化指数(m)和应变率效应因子(Rs)。发现晶粒尺寸不同的镁合金具有各异的应变率强化效应。m和Rs具有较强的相关性,30%轧制量的镁合金m和Rs均大于5%轧制量,250℃退火态的Rs最大,轧制未退火态次之,350℃退火态最小。
AZ31 magnesium alloy sheets are treated through different rolling and annealing procedures.Split Hopkinson Pressure Bar(SHPB) is applied to carry out dynamic compression tests on the cylinder samples and the relationships between microstructures and dynamic behaviors of AZ31 alloy are investigated.The experimental results show that varying grain sizes can be obtain through 5% or 30% third rolling deformation amount plus 250℃ or 350℃ annealing.In the strain rates range of 1.2×103-2.4×103/s,AZ31 magnesium alloys exhibit different strain rate hardening effects due to different grain sizes.According to dynamic stress-strain curves,strain rate hardening exponent m and strain rate effect index Rs are calculated.The values of m and Rs of AZ31 alloy through 30% rolling deformation and 250℃ annealing treatment have highest values.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2009年第S1期219-222,共4页
Journal of Materials Engineering
