CAJ | 학술논문

通过Gleeble-1500试验机对坯料预先经过晶粒细化处理的AZ31镁合金圆柱体试样进行单向热压缩试验,压缩温度为300～450℃,应变速率ε·为0.01s~(-1),0.1s~(-1),1.0s~(-1),根据试样结果分析计算了本构方程中的各参数,获得了完整的镁合金高温本构方程,进一步分析了压缩试样的显微组织.结果表明:在本试验条件下,AZ31镁合金的热变形应力指数n为6.24,热变形激活能为177.2kJ/mol.压缩试样心部组织变形程度明显高于边缘;随着温度的升高,心部压缩组织发生明显的再结晶,新晶粒在晶界处形核并长大.
통과Gleeble-1500시험궤대배료예선경과정립세화처리적AZ31미합금원주체시양진행단향열압축시험,압축온도위300～450℃,응변속솔ε·위0.01s~(-1),0.1s~(-1),1.0s~(-1),근거시양결과분석계산료본구방정중적각삼수,획득료완정적미합금고온본구방정,진일보분석료압축시양적현미조직.결과표명:재본시험조건하,AZ31미합금적열변형응력지수n위6.24,열변형격활능위177.2kJ/mol.압축시양심부조직변형정도명현고우변연;수착온도적승고,심부압축조직발생명현적재결정,신정립재정계처형핵병장대.
Unidirectional hot compressive tests of AZ31 magnesium alloy after grain refinement were performed by Gleeble-1500 machine at strain rates changed among 0.01～1s~(-1) and deformation temperature varied among 300～450℃. Each parameter of the constitutive equation was gained by analyzing and calculating the results of samples, and a complete constitutive equation of AZ31 magnesium alloy for high temperature was fabricated, furthermore, the microstructures of compressive samples were studied. The results show that the hot deformation activation energy Q is 177.181 kJ/mol and the stress exponent n is 6.24. Compared with the edge of the compressive samples, the center has more intense degeneration. With the temperature increasing, obvious recrystallization is observed in the compressive organization. The new grain forms toward the crystal boundary and then grows up.