铸造铝硅合金真空密封造型工艺难点分析

Key Problems Analysis and Countermeasures of Vacuum Sealed Molding Casting Al-Si Alloy

根据真空密封造型工艺和铸造铝硅合金性能特点,分析了真空密封造型用于铝硅合金铸造的难点,主要是铝硅合金容易吸气、氧化,氢在铝液、固态中溶解度差值大,真空密封造型散热慢,铝硅合金的凝固收缩大等。通过妥善保管原材料,做好熔炼前准备;快速熔炼,降低浇注温度,缩短浇注时间;提高冷却速度,增加型腔排气;充分精炼;采用倾转浇注工艺等,问题得到较好解决。经对大型高压开关铝硅合金铸件的生产验证,取得良好的效果。

Problems in vacuum sealed molding casting Al-Si alloy were described based on characteristics of the vacuum sealed molding and cast Al-Si alloy properties,including Al-Si alloy easier to oxidation and inspiration,high difference value of hydrogen solubility in between liquid aluminum and castings,slow heat radiation of vacuum sealed molding and high solidification contraction of Al-Si alloy.It is adopted to successfully produce Al-Si alloy high voltage switch by keeping the raw material properly to make a good preparation before melting and rapidly melting to decrease pouring temperature and time and raising cooling velocity and exhaust degree in cavity,fully refining as well as adopting tilting pouring.