CAJ | 학술논문

采用OM、XRD、SEM和EDS研究不同Sr含量对AM80合金微观组织与力学性能的影响.结果表明,Sr在晶界处发生偏聚,使晶粒长大受阻,从而细化α-Mg基体,Sr在枝晶尖端的富集改变了初生相α-Mg的形貌.随Sr含量增加,出现新相Al4Sr,β-Mg17Al12相含量不断降低直至完全消失.添加Sr可使AM80镁合金的室温力学性能得到明显改善,添加1.5%Sr(质量分数)时效果最好,其抗拉强度和伸长率分别达到最大值160 MPa和15.04%.随Sr含量的增加,AM80镁合金断裂方式由解理断裂向韧性断裂、再向解理断裂方式转变.
채용OM、XRD、SEM화EDS연구불동Sr함량대AM80합금미관조직여역학성능적영향.결과표명,Sr재정계처발생편취,사정립장대수조,종이세화α-Mg기체,Sr재지정첨단적부집개변료초생상α-Mg적형모.수Sr함량증가,출현신상Al4Sr,β-Mg17Al12상함량불단강저직지완전소실.첨가Sr가사AM80미합금적실온역학성능득도명현개선,첨가1.5%Sr(질량분수)시효과최호,기항랍강도화신장솔분별체도최대치160 MPa화15.04%.수Sr함량적증가,AM80미합금단렬방식유해리단렬향인성단렬、재향해리단렬방식전변.
@@@@The effects of Sr addition on the microstructure and mechanical properties of AM80 magnesium alloy were investigated by optical microscopy (OM), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results indicate that the segregation of Sr element at solidification interface front leads to the grain refinement and the blunting ofα-Mg dendrite. With increasing the Sr content, new phases Al4Sr can be observed. Meanwhile, the amount of β-Mg17Al12 phase decreases. The addition of Sr can modify the mechanical properties of AM80 magnesium alloy obviously at room temperature. Among the Sr-containing alloys, the alloy with the addition of 1.5%Sr (mass fraction) exhibits relatively optimal mechanical properties,and the tensile strength and elongation reach the maximum values of 160 MPa and 15.04%. As the Sr content increases, the fracture mechanism of the AM80 alloy at room temperature changes from cleavage fracture to ductile fracture, and then to the cleavage fracture mode.