CAJ | 학술논문

通过在温度为250~450°C和应变速率为0.001~10 s?1条件下进行压缩测试，研究挤压态ZK60A镁合金的高温变形行为和加工性能。ZK60A镁合金的本构方程可以用双曲正弦函数进行描述。在真应变为?0.2~?0.8下构建热加工图。在300~400°C以及0.01~0.001s?1应变速率下，材料完全再结晶(DRX)并显示出良好的加工性能。ZK60A镁合金高温加工，例如锻造，可以进行。在变形量大于?0.5以及应变速率高于0.1 s?1时，实验观察到流变失稳现象，例如局部应变集中、孪生变形、晶粒异常长大、微裂纹和切变断裂，不推荐进行加工。攀移控制的位错蠕变主导ZK60A镁合金的塑性变形以及动态再结晶形核。
통과재온도위250~450°C화응변속솔위0.001~10 s?1조건하진행압축측시，연구제압태ZK60A미합금적고온변형행위화가공성능。ZK60A미합금적본구방정가이용쌍곡정현함수진행묘술。재진응변위?0.2~?0.8하구건열가공도。재300~400°C이급0.01~0.001s?1응변속솔하，재료완전재결정(DRX)병현시출량호적가공성능。ZK60A미합금고온가공，례여단조，가이진행。재변형량대우?0.5이급응변속솔고우0.1 s?1시，실험관찰도류변실은현상，례여국부응변집중、련생변형、정립이상장대、미렬문화절변단렬，불추천진행가공。반이공제적위착연변주도ZK60A미합금적소성변형이급동태재결정형핵。
The hot deformation behavior and workability of pre-extruded ZK60A magnesium alloy were investigated by compression tests in the temperature range of 250?450 °C and the strain rate range of 0.001?10 s?1. The constitutive equation for the pre-extruded ZK60A alloy can be described by hyperbolic sine function. Processing maps were constructed from true strains of?0.2 to?0.8. The alloy experienced complete dynamic recrystallization (DRX) and showed good workability in the temperature range of 300?400 °C and the strain rate range of 0.01?0.001s?1, where hot working in pre-extruded ZK60A, such as forging, can be carried out. For large deformation to true strain of over?0.5, strain rates above 0.1 s?1 are not recommended at all temperatures, where flow instability such as local strain concentration, twinning deformation, abnormal grain growth, micro-cracks, and shear fracture were observed. Climb-controlled dislocation creep dominates both the plastic deformation and nucleation of DRX of the pre-extruded ZK60A magnesium alloy.