CAJ | 학술논문

在Gleeble-1500热模拟仪上进行热压缩实验，研究在变形温度250~450°C、应变速率0.0005~0.5 s-1时淬火状态下的7005铝合金的热变形行为。实验结果表明：淬火状态7005合金的流变应力受变形温度和应变速率的双重影响，热变形过程中的流变应力可用 Zener-Hollomon 参数的指数型方程表示。通过比较本构方程计算出的流变应力和实验测量的流变应力发现预测结果和实验结果有很好的相符性。基于动态材料模型，在真应变为0.1、0.3和0.5处构建了淬火状态下的7005铝合金的热加工图。通过加工图分析及微观组织观察发现合金的最优热加工区域为：270~340°C，0.05~0.5 s-1,在该区域内变形时合金发生了合理的动态再结晶行为。合金的流变不稳定性与绝热剪切带以及局部流变的产生有关。因此，为获取满意的性能，在热加工时应避开这些不稳定的区域。
재Gleeble-1500열모의의상진행열압축실험，연구재변형온도250~450°C、응변속솔0.0005~0.5 s-1시쉬화상태하적7005려합금적열변형행위。실험결과표명：쉬화상태7005합금적류변응력수변형온도화응변속솔적쌍중영향，열변형과정중적류변응력가용 Zener-Hollomon 삼수적지수형방정표시。통과비교본구방정계산출적류변응력화실험측량적류변응력발현예측결과화실험결과유흔호적상부성。기우동태재료모형，재진응변위0.1、0.3화0.5처구건료쉬화상태하적7005려합금적열가공도。통과가공도분석급미관조직관찰발현합금적최우열가공구역위：270~340°C，0.05~0.5 s-1,재해구역내변형시합금발생료합리적동태재결정행위。합금적류변불은정성여절열전절대이급국부류변적산생유관。인차，위획취만의적성능，재열가공시응피개저사불은정적구역。
The compressive deformation behavior of as-quenched 7005 aluminum alloy was investigated at the temperature ranging from 250 °C to 450 °C and strain rate ranging from 0.0005 s-1 to 0.5 s-1 on Gleeble-1500 thermal-simulation machine. Experimental results show that the flow stress of as-quenched 7005 alloy is affected by both deformation temperature and strain rate, which can be represented by a Zener-Hollomon parameter in an exponent-type equation. By comparing the calculated flow stress and the measured flow stress, the results show that the calculated flow stress agrees well with the experimental result. Based on a dynamic material model, the processing maps were constructed for the strains of 0.1, 0.3 and 0.5. The maps and microstructural examination revealed that the optimum hot working domain is 270-340 °C, 0.05-0.5 s-1 with the reasonable dynamic recrystallization. The instability domain exhibits adiabatic shear bands and flow localization, which should be avoided during hot working in order to obtain satisfactory properties.