钠盐对新型Al-10Sn-4Si合金的变质作用

The Effect of Na-Salt on the Modification of New Type Al-10Sn-4Si Alloy

采用钠盐变质剂对新型Ａｌ－１０Ｓｎ－４Ｓｉ轴承合金熔体进行变质处理，结果发现：变质处理不仅可以细化共晶Ｓｉ相，而且可以明显地改善共晶β（Ｓｎ）相的结晶行为，使得β（Ｓｎ）相环绕Ｓｉ粒子凝固并且以近似网状分布于晶界，为均匀化过程中形成均匀的β（Ｓｎ）包Ｓｉ的“包晶”式相组织创造了有利的条件。

New type Al-10Sn-4Si bearing alloy melt was modified by NaSalt. The result indicated that modification not only refined eutectic Si-phase, but also obviously improved the crystallization behavior of eutectic β(Sn) phase, so that the β(Sn) phase solidified around Si-particle and distributed in the crystal boundary with near network. As a result, the favorable condition was established for the formation of uniform β(Sn) coated Si-phase after homogeneous treatment.