CAJ | 학술논문

在温度为220~380°C和应变速率为0.001~1 s-1的条件下进行等温热压缩，研究铸态AZ91D镁合金的变形行为和动态再结晶行为。讨论变形温度和应变速率对动态再结晶行为的影响。结果表明，动态再结晶晶粒的形核和长大极易在高温和低应变速率的条件下发生。为预测动态再结晶的演变过程，在真实应力-应变曲线数据的基础上，提出 AZ91D 镁合金的动态再结晶动力学模型。该模型揭示动态再结晶的体积分数随着真实应变的增加而增加，其增长趋势呈典型的“S”曲线。通过对比发现由动力学模型所预测的结果和微观组织观测的数据具有很好的一致性，验证了所建立的AZ91D镁合金动态再结晶动力学模型的准确性。
재온도위220~380°C화응변속솔위0.001~1 s-1적조건하진행등온열압축，연구주태AZ91D미합금적변형행위화동태재결정행위。토론변형온도화응변속솔대동태재결정행위적영향。결과표명，동태재결정정립적형핵화장대겁역재고온화저응변속솔적조건하발생。위예측동태재결정적연변과정，재진실응력-응변곡선수거적기출상，제출 AZ91D 미합금적동태재결정동역학모형。해모형게시동태재결정적체적분수수착진실응변적증가이증가，기증장추세정전형적“S”곡선。통과대비발현유동역학모형소예측적결과화미관조직관측적수거구유흔호적일치성，험증료소건립적AZ91D미합금동태재결정동역학모형적준학성。
The flow behavior and dynamic recrystallization (DRX) behavior of an as-cast AZ91D alloy were investigated systematically by applying the isothermal compression tests in temperature range of 220-380 °C and strain rate range of 0.001-1 s-1. The effect of temperature and strain rate on the DRX behavior was discussed. The results indicate that the nucleation and growth of dynamic recrystallized grains easily occur at higher temperatures and lower strain rates. To evaluate the evolution of dynamic recrystallization, the DRX kinetics model was proposed based on the experimental data of true stress-true strain curves. It was revealed that the volume fraction of dynamic recrystallized grains increased with increasing strain in terms of S-curves. A good agreement between the proposed DRX kinetics model and microstructure observation results validates the accuracy of DRX kinetics model for AZ91D alloy.