The phosphorous absorption rate is an important parameter for the refining process of hypereutectic Al-Si alloys, which not only influences final P content, but also reflects the evolution of AlP phase in the melt. The changing rules of P absorption rate were studied as kinds of master alloys, the processing parameters, coupling relationship of added solid particles varied. The experimental results show that Al-3P rod alloy appears the highest absorption rate (80%), while Cu-14P appears the lowest absorption rate (13%) under the same melting condition. The higher holding temperature contributes to superior P absorption rate while the more addition results in the lower. As holding time extends, P absorption rate first increases then decreases when achieving the maximum level at 90 min. Moreover, adding proper solid particles, such as TiB2 and TiC, which have a good structural matching relationship with AlP crystal, can dramatically increase P absorption rate.%采用含P中间合金细化过共晶铝硅合金时,P吸收率是影响合金最终P残留量和Si细化效果的关键因素.研究P吸收率与中间合金种类、熔炼工艺参数以及耦合添加外来微米粒子的相关性,并分析其与AlP相在熔体中演变行为的内在联系.结果表明:熔炼工艺相同时,5种中间合金的吸收率有一定差异,杆状Al-3P的P吸收率最高,可达80%;而Cu-14P的最低,仅为13%.随着熔体温度升高,P吸收率显著提高;随着保温时间延长,P吸收率呈现先增加后减小的趋势;保温90 min时,P吸收率达到极大值;随着加入量增加,P吸收率呈现不断下降趋势.此外,在铝合金熔体中引入与AlP有结构匹配关系的TiB2、TiC等微米粒子,可与未溶解之AlP耦合在一起,起到固定AlP粒子的作用,显著提高P吸收率.
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