铝合金压铸件的表层组织对铸件使用性能有重要的影响。研究不同快压射速度下ADC12铝合金压铸件的表层组织特征,并通过金相和数值模拟进行分析。结果表明,压铸件存在3种不同特征的表层组织:仅含有一层富集致密的初生α-Al相;外层为正常的压铸凝固组织(初生α-Al相和共晶相)邻接细小的初生α-Al相层;属正常的压铸凝固组织。同时,探讨了快压射速度和型腔位置对表层组织的影响。 Aluminum alloy die-casting surface organization of castings have a significant impact on the performance. The surface texture of ADC12 aluminum alloy die-castings at different rapid shot velocities was studied and analyzed by metallographic and numerical simulation. The results show that there are three kinds of surface microstructure with different characteristics: only one layer of dense primary α-Al phase is contained; the outer layer is normal die-casting solidified structure (primary α-Al phase and eutectic phase) Primary α-Al phase layer; is a normal die-casting solidification organization. At the same time, the effects of rapid injection velocity and cavity location on the surface tissue were discussed.