孔洞对AZ91D镁合金压铸件性能的影响

基于ansys软件，研究了孔洞形状、尺寸、位置及孔洞间距离对AZ91D镁合金压铸件的应力分布影响。结果表明：孔洞形状的影响取决于尖角顶点与孔洞中心的连线和受力方向之间的最小夹角，夹角越大应力集中越大：随孔洞尺寸的增加铸件的应力集中增加；位于铸件表面的孔洞造成的应力集中大于内部相同大小的孔洞：孔洞之间距离超过某一临界值时影响很小，当小于该临界值时随孔洞间距离的减小应力集中急剧增加。最后实测了不同工艺条件下生产的AZ91D镁合金发动机缸盖罩盖的孔洞分布形态与强度之间的关系，验证了模拟结果。

A Analyze about the Influence of Hole on Tensile Strength of AZ91D Mg Alloy Die Casting

Based on Ansys software, the influences of shape, size, position and pitch of holes on AZ91D Mg alloy die casting stress distribution were studied. The results show that the influences of shape of hole on stress distribution lie on the minimum included angle formed by two lines, one line is x axis, the other is the tie line of sharp corner apex and center of hole. The stress concentration increases with the increases of the minimum inclination and the size of hole. The influence effect of the open hole is greater than the inner hole. The influence is very faint when the pitch of holes is beyond a critical value, and the stress concentration increases quickly with the decrease of the pitch of holes. Lastly, the hole distribution and the strength of AZ91D Mg alloy for engine head mantle die casting are actually measured. It is shown that the results of theoretical analysis are in consonance with the experiments.