CAJ | 학술논문

目的：研究高温拉伸应力状态下,2024铝合金板材的流变行为和微观组织演化行为。方法对退火后的2024铝合金板进行等温拉伸试验,得到其应力应变曲线,并通过金相实验测定平均晶粒尺寸。建立了2024铝合金板材高温拉伸条件下的流变应力本构关系和晶粒尺寸模型。结果流变应力随温度的升高而减小。流变应力对应变速率有正的敏感性,随着温度的升高,应变速率敏感系数变大。变形后的平均晶粒尺寸随Zener-Hollomon参数升高而减小,随应变量的增加先减小后增大。结论所建立的流变应力本构关系和晶粒尺寸模型,有助于在实际生产过程中优化工艺参数,获得细小晶粒,提高零件性能。该研究为2024铝合金板材热成形工艺的开发和组织控制奠定了理论基础。
목적：연구고온랍신응력상태하,2024려합금판재적류변행위화미관조직연화행위。방법대퇴화후적2024려합금판진행등온랍신시험,득도기응력응변곡선,병통과금상실험측정평균정립척촌。건립료2024려합금판재고온랍신조건하적류변응력본구관계화정립척촌모형。결과류변응력수온도적승고이감소。류변응력대응변속솔유정적민감성,수착온도적승고,응변속솔민감계수변대。변형후적평균정립척촌수Zener-Hollomon삼수승고이감소,수응변량적증가선감소후증대。결론소건립적류변응력본구관계화정립척촌모형,유조우재실제생산과정중우화공예삼수,획득세소정립,제고령건성능。해연구위2024려합금판재열성형공예적개발화조직공제전정료이론기출。
ABSTRACT:The aim of this work was to study the flow behavior and microstructure evolution of 2024 aluminum alloy sheet during hot tension deformation. The 2024 aluminum alloy sheet was stretched to get the true stress-strain curves when the range of deformation temperature was 300 ℃ ~450 ℃ and the range of strain rate was 0. 001 s-1 ~0. 1 s-1 , after the deformation, metallographic tests were carried out on the deformed samples to determine the average grain size. The flow stress constitutive relationship and grain size model for 2024 aluminum alloy sheet under hot tension condition were estab-lished using the experiment results. The flow behavior decreased with the increase of temperature. The flow behavior had a positive sensitivity to the strain rate. With the increase of temperature, the sensitivity coefficient of strain rate became lar-ger. After deformation, the average grain size decreased with the increase of Zener-Hollomon parameter. With the increase of strain, the average grain size first decreased and then increased. The flow stress constitutive relationship and grain size model established were conductive to optimize the process parameters, obtain fine grains and improve the performance of parts in the process of actual production. This study provided a theoretical basis for the development of hot forming process and control of microstructure of 2024 aluminum alloy sheet.