稀土钇对AlZnMgCu合金组织及性能的影响

Effects of Yttrium on Microstructure and Mechanical Properties of AlZnMgCu Alloy

利用金相显微镜、图象分析仪、ＳＥＭ、Ｘ射线衍射仪等实验手段，研究了单一稀土钇（Ｙ）对航空用铝合金ＡｌＺｎＭｇＣｕ铸态组织和力学性能的影响规律．实验结果表明，少量稀土钇能细化合金的二次枝晶组织，减小共晶化合物尺寸．钇的加入主要和铜（Ｃｕ）、硅（Ｓｉ）等元素结合生成相应的稀土化合物相．研究发现。

The effects of Yttrium on the ascast microstructure and the mechanical properties of the AlZnMgCu alloys have been investigated by means of optical microscope,image analyzer,SEM and Xray diffractometry etc. The experimental results show that both the secondary dendrite arm spacing and the eutectic compound demension can be decreased by adding Yttrium. Yttrium can mainly form some intermetallic compounds with CuAl and some impurities, such as Si.It is found that the impact toughness of AlZnMgCu alloys can be improved efficiently by adding a small amount of yttrium.