过共晶Al-Si合金的变质处理试验

Modification Experiment of Hypereutectic Al-Si Alloy

根据Sr、P对过共晶Al-Si合金的变质机理,用Al-Sr(10%)合金、Al-P(3.5%)合金和C还原磷酸钠(赤P∶Na_3PO_4∶石墨C=1∶5.3∶2.5)分别对过共晶Al-Si合金进行变质处理。结果表明,过共晶Al-Si合金用Al-P(3.5%)合金变质效果最佳,显微组织下初生硅数量增多且呈球形均匀弥散分布,Al-P(3.5%)合金加入量在总量的1.1%~1.2%之间,最佳变质时间为20min左右,最稳定的变质温度应控制在780~810℃温度区间。

According to the modification mechanism,hypereutectic Al-Si alloys were modified respectively by Al-Sr(10%)alloy,Al-P(3.5%)alloy and carbon-reducing sodium phosphate(red phosphorus∶Na3PO4∶graphic electrode=1∶5.3∶2.5).The results showed that hypereutectic Al-Si alloy using Al-P(3.5%)alloy has best modification effect in industrial production.The number of primary silicon in the microscopic structure was increased and the distribution was uniform.The addition of Al-P(3.5%)alloy was between 1.1%and 1.2%of the total amount.The best metamorphism time was about 20 minutes.The most stable metamorphic temperature should be controlled in 780-810℃temperature range.