Si，La对Al-4．5Cu合金准固态凝固行为的影响

Effect of Si and La on the Quasi-Solid Solidification Behavior of Al-4.5Cu Alloy

摘要:

通过对合金的收缩应变和热裂抗力及准固态拉伸行为进行测试，研究了合金元素(Si，La)对Al-4．5Cu合金凝固行为的影响。结果表明，Si，La能使Al-4．5Cu的热裂倾向性降低；加入2％Si使合金的再辉现象非常严重，导致合金不可能有很高的强度而很快断裂：与其它Al-4．5Cu-Si合金相比，Al4．5Cu3Si合金具有很强的补缩能力，断裂应力值最高：La的加入能缩小二次枝晶间距，明显提高合金的抗热裂性能。

Abstract:

The effect of alloy elements on the quasi-solid solidification behavior of Al-4.5Cu alloy has been studied. The results indicate that Si and La can reduce the hot cracking tendency of Al-4.5Cu; adding 2%Si to matrix, the releasement of crystallization enthalpies makes the recalescence very severe, so the alloy cracks and cant have high strength; Al4.5Cu3Si has a strong ability of compensation and its fracture stress is highest among the Al-Cu-Si alloys; adding of La can reduce the secondary dendrite arm spacing, and the hot cracking properties are improved obviously.