【摘要】 采用金相、透射电镜、扫描电镜、拉伸试验等测试手段 ,研究了不同含量的稀土元素钪对 70 0 5铝合金组织性能的影响。加入适量钪合金化可以明显细化合金组织 ,改变主要强化相 η相的尺寸、形状、分布 ,减小晶界无沉淀带宽度 ,可以明显提高合金强度、塑性以及高温稳定性 ,这是合金中析出了与铝基体完全共格的Al3 Sc (fcc ,a =0 .41nm)质点所致。更多还原

【Abstract】 Effect of the various content of rare earth element scandium on microstructures and tensile properties of 7005 aluminium alloy was investigated by means of optical microscopy, transmission electron microscopy, scanning electron microscopy and tensile test. The results show that, adding the appropriate amount of scandium will obviously make microstructures of this alloy fine, ametliorate the size, shape and distribution of the primary strenghthening phase (η phase) and reduce the width of precipitation free zone along the grain boundary, and then improve greatly strength and plasticity and elevated temperature thermal stability of the materials. The advantageous effects are mainly due to completely coherent Al 3Sc (fcc, a =0.41 nm) precipitated from the aluminium matrix.更多还原