CAJ | 학술논문

采用Gleeble热模拟方法研究Mg?6Zn?1Al?0.3Mn 变形镁合金在温度为200~400°C，应变速率为0.01~7 s?1条件下的热压缩变形行为。结果表明，变形温度和应变速率显著影响其热变形行为。通过计算获得了热变形激活能及应力指数分别为Q=166 kJ/mol，n=5.99，且其本构方程为ε&=3.16×1013[sinh(0.010σ)]5.99exp [?1.66×105/(RT)]。热压缩显微组织观察表明：在应变速率为0.01~1 s?1的条件下，在250°C热压缩变形时初始晶粒晶界及孪晶处发生了部分动态再结晶，而在高温(350~400°C)条件下，发生了完全动态再结晶且再结晶晶粒尺寸随着应变速率的增加而减小。获得的较优的变形条件为温度330~400°C、应变速率为0.01~0.03 s?1以及350°C、应变速率为1 s?1。
채용Gleeble열모의방법연구Mg?6Zn?1Al?0.3Mn 변형미합금재온도위200~400°C，응변속솔위0.01~7 s?1조건하적열압축변형행위。결과표명，변형온도화응변속솔현저영향기열변형행위。통과계산획득료열변형격활능급응력지수분별위Q=166 kJ/mol，n=5.99，차기본구방정위ε&=3.16×1013[sinh(0.010σ)]5.99exp [?1.66×105/(RT)]。열압축현미조직관찰표명：재응변속솔위0.01~1 s?1적조건하，재250°C열압축변형시초시정립정계급련정처발생료부분동태재결정，이재고온(350~400°C)조건하，발생료완전동태재결정차재결정정립척촌수착응변속솔적증가이감소。획득적교우적변형조건위온도330~400°C、응변속솔위0.01~0.03 s?1이급350°C、응변속솔위1 s?1。
The hot compression behavior of a wrought Mg?6Zn?1Al?0.3Mn magnesium alloy was investigated using Gleeble test at 200?400 °C with strain rates ranging from 0.01 to 7 s?1. The true stress-strain curves show that the hot deformation behavior significantly depends on the deformation temperature and strain rate. The calculated hot deformation activation energy Q is 166 kJ/mol with a stress exponent n=5.99, and the constitutive equation is deduced to be ε& =3.16×1013[sinh(0.010σ)]5.99exp [?1.66×105/(RT)]· Deformation microstructure shows that the incompletely dynamically recrystallized grains can be found at grain boundaries and twins with the strain rates ranging from 0.01 to 1 s?1 at 250 °C, and completely dynamic recrystallization occurs when the temperature is 350 °C or above during hot compression, the size of recrystallized grains decreases with the increment of the strain rate at the same temperature. The relatively suitable deformation condition is considered temperature 330?400 °C and strain rate of 0.01?0.03 s?1, and temperature of 350 °C and strain rate of 1 s?1.