稀土La及Sn对铸造铝合金组织、力学和阻尼性能的影响

研究了稀土La对含质量分数4%Sn铸造铝合金组织、阻尼和力学性能的影响,从La对Sn的形态和分布、La对Sn和铝合金基体润湿特性的影响等方面探讨了阻尼提高机制。结果表明,La含量为0.2%时,4%Sn的AlMgMnSi合金晶粒尺寸得到细化,β-Sn由大颗粒状变为细小、弥散分布,继续提高La含量至0.83%,晶粒变大,且在晶界处出现块状稀土化合物。La的加入可以有效提高含4%Sn铸造铝合金的阻尼性能,当La添加量为0.2%时,含4%Sn的AlMgMnSi和ZL102合金分别比不添加La的提高了约70%和100%。La改善了β-Sn与铝基体的润湿性,使β-Sn呈弥散、细小分布,从而有利于提高相界面阻尼,是本试样具有较高阻尼性能的主要原因。

The mechanism of Rare Earth La improving the damping property of cast aluminum alloy with 4wt.% Sn

The influence of rare earth La on the microstructure,damping and mechanical properties of cast aluminum alloy containing 4 wt%Sn was studied.The damping improvement mechanism was discussed from the effect of La on the morphology and distribution of Sn,and wetting characteristics of Sn and aluminum alloy matrix.The results show that when the La content is 0.2 wt%,the grain size of Al Mg Mn Si alloy containing 4 wt%Sn is improved,and theβ-Sn charges from large granular to fine,and dispersively distributed.As the La content increases to 0.83 wt%,the grain size becomes larger and the bulk rare earth compounds appear at grain boundary.The addition of La can effectively improve the damping performance of the cast aluminum alloy containing 4 wt%Sn.When the La addition amount is 0.2 wt%,the damping property of Al Mg Mn Si with 4 wt%Sn and ZL102 alloy increases by about 70%and 100%,respectively.La improves the wettability ofβ-Sn and aluminum matrix,and makes theβ-Sn exhibit dispersion and fine distribution,thus improving the phase interface damping,which is the reason for the high damping performance of the samples.