CAJ | 학술논문

研究T4和T6热处理状态下高真空压铸Mg?8Gd?3Y?0.4Zr(质量分数，%)合金的微观组织、化合物含量、力学性能及断裂行为。铸态Mg?8Gd?3Y?0.4Zr合金微观组织主要由α-Mg和共晶Mg24(Gd,Y)5化合物组成。经固溶处理后，共晶化合物大量溶解于镁基体，合金主要含过饱和α-Mg及方块相。固溶合金中方块相的含量随固溶温度的升高而增大，力学性能也有所提高。根据微观组织结果，确定475°C，2 h为Mg?8Gd?3Y?0.4Zr合金最优固溶方案。合金的最佳屈服强度为222.1 MPa，延伸率可达15.4%。铸态，T4状态下和T6状态下合金的拉伸断裂模式为穿晶准解理断裂。
연구T4화T6열처리상태하고진공압주Mg?8Gd?3Y?0.4Zr(질량분수，%)합금적미관조직、화합물함량、역학성능급단렬행위。주태Mg?8Gd?3Y?0.4Zr합금미관조직주요유α-Mg화공정Mg24(Gd,Y)5화합물조성。경고용처리후，공정화합물대량용해우미기체，합금주요함과포화α-Mg급방괴상。고용합금중방괴상적함량수고용온도적승고이증대，역학성능야유소제고。근거미관조직결과，학정475°C，2 h위Mg?8Gd?3Y?0.4Zr합금최우고용방안。합금적최가굴복강도위222.1 MPa，연신솔가체15.4%。주태，T4상태하화T6상태하합금적랍신단렬모식위천정준해리단렬。
The microstructure, the content of compounds, mechanical properties and fracture behavior of high vacuum die casting Mg?8Gd?3Y?0.4Zr alloy (mass fraction, %) under T4 condition and T6 condition were investigated. The microstructure for the as-cast Mg?8Gd?3Y?0.4Zr alloy mainly consists ofα-Mg and eutectic Mg24(Gd,Y)5 compound. After solution treatment, the eutectic compounds dissolve massively into the Mg matrix. The main composition of solution-treated alloys is supersaturated α-Mg and cuboid-shaped phase. The T4 heat treated samples have increasing cuboidal particles with the increase of heat treatment temperature, which turn out good mechanical properties. The optimum T4 heat treatment for high vacuum die cast Mg?8Gd?3Y?0.4Zr alloy is 475 °C, 2 h according to microstructure results. The optimum ultimate strength and elongation of solution-treated Mg?8Gd?3Y?0.4Zr alloy are 222.1 MPa and 15.4%, respectively. The tensile fracture mode of the as-cast, and T6 heat treated alloys is transgranular quasi-cleavage fracture.