Al—Si合金共晶阶段强迫流动下的Si相形态

Morphology of Si Phase in Al-Si Alloys by ForcedFlow during Eutectic Reaction

研究了三种Al-Si合金在熔体流动下的Si相形态和共晶凝固特点,结果表明:在强迫流动熔体中生长的共晶Si形态取决于流动速度、疑团速度和共晶凝固分数,共晶Si由片状变为颗粒状和短棒状.文中对粒化机理进行了分析,提出了一种共晶si粒化的新途径.近共晶流变Al-Si合金中的离异共晶,分为三种类型:薄膜、晕轮和Si相与α相分别单独生长型.

The morphology of Si phase and characteristics of eutectic solidification in three Al-Si alloys were investigated under melt flow during eutectic rea-ction.lt was shown that the shape of eutectic silicons growing in forced flow melt depended upon the flow rate, solidification rate and solidified eutectic fraction.The eutectic silicons became togranulous and short thick laminar from ordinary flake. An analysis has been made on the granulating mechanism, and a new route of eutectic Si granulation has been proposed. The divorced eutectics in rhoecasting Al-Si near eutectic alloys have been devided into three types:film modle,halo modle and formation of individual particles of Si and α phases.