ZnS颗粒大小对Al-24Si合金变质效果的影响

Effect of the Size of Zn S Particle on Modification of Al-24Si Alloy

采用水热法制备了三种不同颗粒尺寸的ZnS粉末,以ZnS颗粒为Al-24Si过共晶铝硅合金的变质剂并通过外加的方式加入其中,研究了ZnS的粒径大小、分散度对其变质效果的影响。结果表明,在一定范围内,ZnS颗粒的粒径越小,分散度越好,变质细化效果就越好,可将初晶硅的平均尺寸细化至30μm以下。最后结合传统异质形核理论对ZnS变质机理进行了分析讨论。

Three kinds of ZnS powders with different particle sizes were prepared by hydrothermal method.The ZnS particles were used as modifiers of hypereutectic Al-24 Si alloy and were added by external mean.The influences of particle size and dispersity of ZnS on the modification effect were studied.The results show that,in a certain range,the smaller the particle size of ZnS is,the better the dispersion is,the better the refinement effect is.The average size of the primary silicon can be refined to 30μm or less.Combined with the traditional heterogeneous nucleation theory,the modification mechanism of ZnS was analyzed and discussed.