3种铝合金材料动态性能及其温度相关性对比研究

 对3种铝合金2024-T351、7050-T7451和LY12-CZ进行了温度在77～573 K的静、动态压缩（应变率10^-3～6 000/s）和拉伸（应变率10^-3～3 000/s）试验，分别得到了3种铝合金材料的应力 应变关系和失效应变。对比研究结果表明，随温度升高3种材料的塑性流动应力降低，应变率敏感性增加。最后基于Johnson-Cook模型，拟合了用以预测铝合金材料塑性流动应力的模型参数，其预测结果与试验结果吻合较好。

Comparison of Mechanical Properties and Their Temperature Dependencies for Three Aluminium Alloys Under Dynamic Load

The compression and tension tests of three aluminium alloys,2024-T351,7050-T7451 and LY12-CZ,are carried out at the temperature from 77 K to 573 K,the compression strain rate is from 10-3/s to 6 000/s and the tension strain rate is from 10-3/s to 3 000/s.The stress-strain relationship and the failure strain of three aluminium alloys are obtained separately.The comparative research on the mechanical properties of these three materials shows that the flow stress is not sensitive to the strain rate at room temperature;but the sensitivity of strain rate increases and the flow stress decreases with the temperature rising.The coupling effect between strain rate and strain is not visible.The higher strain rate under dynamic load brings the temperature rising of the sample which reduces the flow stress of the sample.The failure strain decreases with increasing strain rate and the 7050-T7451 has the minimum failure strain among three aluminium alloys at the same strain rate.Finally,all the parameters of the model based on Johnson-Cook model are determined by curve-fitting.The prediction results based on the corresponding model agree fairly with the experimental data.