基于正交试验的过共晶Al-20Si合金变质工艺优化设计

摘要

Based on L9(34) orthogonal experiment, modification treatments was made of hypereutectic Al-20Si alloys in this pa-per. Through direct analysis and variance analysis, the best process parameter of modification was determined. The results show that, the best process parameter of orthogonal experiment is A2B2C1D2, which is the quantity added of P is 0.04%, mixed rare earth is 0.6%, the modification time is 20min and the modification temperature is 780oC. The morphology of primary Si phase became regular hexa-gons and the average size were 24.84μm, eutectic Si phase were refined significantly;Factor A(the quantity added of P) has an obvi-ous influence on modification effect, while B、C、D(mixed rare element, modification time and modification temperature) have some certain effects on modification effect. The extent of influence of these factors is the quantity added of P>mixed rare element>modifica-tion time>modification temperature.%基于L9(34)正交试验，本文对过共晶Al-20Si合金进行变质处理。通过直观和方差分析，确定最佳的变质工艺参数。结果表明：正交试验最佳的工艺参数为A2B2C1D2，变质工艺参数为0.04%的P添加量，0.6%的RE混合稀土添加量，20 min的变质时间以及780℃的变质温度，此时初生Si相转变为规则的六边形，平均尺寸为24.84μm，共晶硅相细化明显；因素A （P添加量）对变质效果有显著影响，B、C、D因素（分别为RE混合稀土添加量、变质时间和变质温度）对变质效果有一定的影响作用，各因素的影响程度分别为P添加量>RE混合稀土添加量>变质温度>变质时间。