高温、高应变率LY12铝压缩动态力学性能实验

利用配备自动组装系统和高温加热系统的直径为 ф5 mm的Hopkinson压杆,对温度在20℃～400℃、应变率在(5～14)×103s-1范围内LY12铝的动态压缩力学性能进行了实验研究.实验中采用波形整形技术,有效地消除了入射波的高频振荡,提高了测试精度.实验结果表明:当实验温度低于200℃时,温度的影响较小,而高于200℃时,材料的温度软化效应将十分明显,且随着温度的升高,流动应力逐步降低;LY12铝的性质接近于线性硬化材料,随温度的升高,其硬化模量逐步降低;在(5～14)×103s-1应变率范围内,LY12铝的动态压缩性能的应变率效应并不明显. 

Experimental investigation into dynamic compressive mechanical properties of LY12 at high strain rates and high temperatures

The dynamic mechanical properties of LY12 aluminum were studied experimentally by Hopkinson Bar of diameter 5mm with an automatic assembling system and heating system,within the range of temperature from 20℃ to 400℃ and strain-rate from 5×103s-1 to 1.4×104s-1.In the experiments,a shaper was used to eliminate the oscillation of high frequency in the incident signal and to improve the experimental precision of bar system.The experimental results show that the effect of temperature on dynamic properties of LY12 is not great at temperature lower than 200℃;on the contrary,the thermal softening effect is obvious at temperature higher than 200℃,exhibiting the decrease of flow stresses and linear harden modulus with increase of temperature,which is similar to linear harden materials.From the experiments,the dynamic properties of LY12 don't show strong sensitivity to the strain rates.