CAJ | 학술논문

7075铝合金在热变形过程中主要发生连续动态再结晶，在温度为250~450℃、应变速率为0.1~1 s?1的条件下，对多组圆柱试样进行热模拟压缩实验。采用金相定量法对热变形后材料的显微组织晶粒度进行测量，建立7075铝合金热变形时动态再结晶晶粒度演化模型。结果表明：根据唯象理论的指数模型，利用线性回归方法求得7075铝合金热塑性变形组织晶粒度的演化模型；将该模型导入到有限元软件中能够预报7075铝合金热变形过程的连续动态再结晶晶粒度；预报结果与实验结果非常接近，说明将该演化模型导入有限元软件中可以较为准确地预测7075铝合金热变形过程动态再结晶晶粒度。
7075려합금재열변형과정중주요발생련속동태재결정，재온도위250~450℃、응변속솔위0.1~1 s?1적조건하，대다조원주시양진행열모의압축실험。채용금상정량법대열변형후재료적현미조직정립도진행측량，건립7075려합금열변형시동태재결정정립도연화모형。결과표명：근거유상이론적지수모형，이용선성회귀방법구득7075려합금열소성변형조직정립도적연화모형；장해모형도입도유한원연건중능구예보7075려합금열변형과정적련속동태재결정정립도；예보결과여실험결과비상접근，설명장해연화모형도입유한원연건중가이교위준학지예측7075려합금열변형과정동태재결정정립도。
Continuous dynamic recrystallization (CDRX) of 7075 aluminum alloy occurs during hot deformation. The thermal compression experiment about the group of cylindrical specimen was done at the temperature of 250?450 ℃and the strain rate of 0.1?1 s?1. The microstructure grain size of 7075 aluminum alloy was measured by the metallographic quantitative method, the microstructure grain size evolution model of 7075 aluminum alloy. The result shows that, according to the exponential model of phenomenological theory and the linear regression method, the microstructure grain size evolution model of 7075 aluminum alloy during the thermoplastic deformation can be worked out. And then, by the finite element software with the evolution model continuous dynamic recrystallization grain size of 7075 aluminum alloy during hot deformation was predicted. The forecasting result is very close to the experimental one. Therefore, by finite element software with the evolution model, dynamic recrystallization grain size of 7075 aluminum alloy during the hot deformation process can be accurately predicted.