CAJ | 학술논문

熔炼并浇注了Mg2Si增强AZ91D复合材料铸锭，并研究了Si含量对其铸态组织和力学性能的影响规律。结果表明：Mg2Si增强AZ91D复合材料中初生Mg2Si数量随着Si含量的增加而增多，其形状由细小的树枝状、块状、颗粒状变成粗大的树枝状。Si含量为2%时，初生Mg2Si最细小，平均晶粒尺寸达到15μm。随着Si含量的增加，Mg2Si增强AZ91D复合材料室温力学性能呈下降的变化趋势，Si含量为2%时，室温抗拉强度、条件屈服强度、伸长率分别达到281 MPa、132.3 MPa和6.4%。Si含量为2%时，Mg2Si增强AZ91D复合材料拉伸断口中出现了许多韧窝，撕裂棱非常明显，说明材料的塑性较好。
용련병요주료Mg2Si증강AZ91D복합재료주정，병연구료Si함량대기주태조직화역학성능적영향규률。결과표명：Mg2Si증강AZ91D복합재료중초생Mg2Si수량수착Si함량적증가이증다，기형상유세소적수지상、괴상、과립상변성조대적수지상。Si함량위2%시，초생Mg2Si최세소，평균정립척촌체도15μm。수착Si함량적증가，Mg2Si증강AZ91D복합재료실온역학성능정하강적변화추세，Si함량위2%시，실온항랍강도、조건굴복강도、신장솔분별체도281 MPa、132.3 MPa화6.4%。Si함량위2%시，Mg2Si증강AZ91D복합재료랍신단구중출현료허다인와，시렬릉비상명현，설명재료적소성교호。
In this study, the AZ91D composite casting reinforced by Mg2Si is melted and poured, and we explore the effects of Si content on its cast structure and mechanical properties. The results indicate that, for Mg2Si/AZ91D composites, the number of primary Mg2Si increases while the Si content increases and their shape turns from tiny branches, bulk and graininess into the thick branches. When Si content is 2%, primary Mg2Si is finest andthe average grain size reaches 15μm. With the Si content increasing, the mechanical properties of room temperature of in-situ Mg2Si/AZ91D composites decrease. Meanwhile, the tensile strength of room temperature, offset yield strength and elongation is 281MPa, 132.3MPa and 6.4% respectively. Under this content, many dimples appear in the tensile fractures of Mg2Si/AZ91D composites and the tear ridges are very obvious. This illustrates that the plasticity of the material is better.