混合稀土变质对ZL101铝合金组织和性能的影响

Effect of mixed rare-earth modification on microstructure and properties of ZL101 aluminum alloy

运用金相显微镜、扫描电镜、能谱仪等设备,研究了镧铈混合稀土对ZL101铝合金组织和性能的影响,同时考察固溶、时效对变质及未变质合金微观组织和性能的影响。结果表明：稀土变质可有效地促进初生相的粒状化,针状共晶硅由在晶界聚集变得分散,并且尺寸也有所减小,但对合金力学性能的提高程度不明显。经过固溶、时效处理后,α（A l）和共晶硅的形态明显改善,α（A l）由树枝状、花瓣状变为粒状、等轴状,共晶硅则几乎全部变为球状且呈弥散分布,合金的力学强度性能提高幅度比铸态试样的大,增加幅度平均为90 N/mm2~110 N/mm2。

The effect of mixed rare-earth（Ce,La） modification on microstructure and mechanical properties of ZL101 alloy have been investigated by optical microscope,SEM and EDS,the effect of solid-solution aging on microstructure and mechanical properties of both modified and non-modified alloy have been analyzed as well.The results show that the RE modifier can promote granulation of newborn phases;made the gathered needle eutectic silicon phases scattering form the grain boundary,and their size gets smaller;while the mechanical properties of the alloy are not improved evidently.After solid solution treatment,āphase and eutectic silicon have been improved,ā tree and rose crystals become granular or iso-axial,almost all the eutectic silicon phases turn into granular and diffusible,the mechanical properties of the alloy are increased more than that of cast samples,the average increment are 90 N/mm2-110 N/mm2.