CAJ | 학술논문

在变形温度为523-673 K,应变速率为0.001-1s-1的条件下,采用Gleeble-1500热模拟试验机对ZK60镁合金的热变形行为进行了研究.结果表明,ZK60镁合金流变应力随变形温度升高和应变速率的降低而减小.其高温压缩流变应力曲线可描述为加工硬化、过渡、软化和稳态流变4个阶段,但在温度较高和应变速率较小时,过渡阶段不很明显.建立了-个包含应变的流变应力预测模型,模型中的9个独立参数可以通过非线性最小二乘法拟合求得,预测的流变应力曲线与实验结果吻合较好.
재변형온도위523-673 K,응변속솔위0.001-1s-1적조건하,채용Gleeble-1500열모의시험궤대ZK60미합금적열변형행위진행료연구.결과표명,ZK60미합금류변응력수변형온도승고화응변속솔적강저이감소.기고온압축류변응력곡선가묘술위가공경화、과도、연화화은태류변4개계단,단재온도교고화응변속솔교소시,과도계단불흔명현.건립료-개포함응변적류변응력예측모형,모형중적9개독립삼수가이통과비선성최소이승법의합구득,예측적류변응력곡선여실험결과문합교호.
In order to study the workability and establish the flow sttess constitutive equation for ZK60 magnesium alloy,hot compressive deformation behavior of the magnesium auoy was investigated at the temperature range from 523 to 673 K and strain rate range from 0.001 to 1 S-1 on Gleeble-1500 thermal simulator.The results show that flow stress of ZK60 magnesium alloy decreases with the increase of deformation temperature and the decrease of strain rate.The flow stress curves obtmned from experiments are composed of four difierent stages,I.e.,work hardening,transition,softening and steady stages.While for the relative high temperature and low strain rate,transition stage is not very obvious.A method to predict flow stress considering the efrect of true strain was presented.Flow stress model is expressed by nine independent parameters and they are obtained by Least-Square method.The predicted stress-strain curves are in good agreement with the experimental results,which confirmed that the developed model can give a reasonable estimate of the flow stress for ZK60 magnesium alloy.