熔炼铝合金时,由于炉料、熔化工具带进水分和合金吸气等因素使铝液中含有大量的氢,氢在铝合金液中有较大的溶解度,但随温度降低,溶解度减少,在凝固过程中大量析出,而形成针孔。为此,铝合金熔炼时,通常必须进行精炼——除气处理,以提高铝铸件质量。很多工厂以往常用氯化锌或六氯乙烷精炼。氯化锌易吸潮,如精炼前脱 When smelting aluminum alloy, the molten aluminum contains a large amount of hydrogen due to factors such as charge, ingress of water into the melting tool and suction of the alloy, and the hydrogen has greater solubility in the aluminum alloy liquid. However, as the temperature decreases, the solubility decreases, A large number of precipitation process, and the formation of pinholes. To this end, aluminum smelting, usually must be refined - degassing to improve the quality of aluminum castings. Many factories used to use zinc chloride or hexachloroethane refining. Zinc chloride easily absorb moisture, such as refining before off