对Mg-3%Li-1%Sc合金进行热轧及退火处理,采用Hopkinson压杆对合金进行冲击压缩试验,分析了轧制及退火处理对合金冲击行为的影响。结果表明,在应变率1350-2400 s^-1范围内,热轧及退火处理后合金的动态屈服强度随应变率增加而明显提高,且合金的动态变形行为呈现为应变率强化效应。当应变率进一步提高至2800 s^-1时,合金的动态变形行为又表现为应变率弱化效应。裂纹的出现是合金产生应变率弱化效应的主要原因。
Mg-3%Li-1%Sc alloy was rolled followed by annealing treatment.The impact experiment for the alloy was conducted by Split Hopkinson Pressure Bar.The effect of hot rolling and the following annealing treatment on the impact behavior of Mg-3%Li-1%Sc alloy was investigated.The results show that in the strain rates range from 1350 s-1 to 2400 s-1,the dynamic yield strength of the rolled and annealed Mg-3%Li-1%Sc alloy is significantly improved with increasing the strain rates,and the dynamic stress-strain behaviors of the rolled and annealed alloy exhibit positive strain rate effect.While the strain rate increases to 2800 s-1,the dynamic stress-strain behaviors of the alloy exhibit negative strain rate effect.The crack in the alloy makes the primary contribution to the negative strain rate effect of the alloy.