Preparation Process And Theory Of Semi-solid Al-25%Si Alloy By Electromagnetical Stirring

The semi-solid hypereutectic Al-25%Si alloy sully was prepared by electromagnetical stirring,which is an exploring job to extend application field of Al-Si alloy material.The hypereutectic Al-Si alloy is an important light anti-wear material and the electromagnetical method is an new forming technology which can be used to prepared economically:So the study of the thesis is provided greatly practical value to material exploitation and production application.The preparation process of semi-solid hypereutectic Al-25%Si alloy slurry poured at electromagnetical stirring in this text.The effect of stirring temperature, power and treating time on microstructure and synthetical application properties of slurry were discussed.The microstructure evolvement mechanism of alloy was previously analyzed in electromagnetical stirring.Then the primary conclusions were obtained as following:1)The relative perfect semi-solid hypereutectic Al-25Si%alloy slurry could be prepared by electromagneticcal stirring,which improved the appearance,the size and the distributing of primary silicon.So the synthetical application properties of slurry heightened and stirring temperature,power and treating time affected the slurry structure and properties.2)In the condition of the lab,both good structure and properties semi-solid hypereutectic Al-25%Si alloy slurry was prepared when the stirring temperature was 580℃and stirred by 4.8kW for 20min～30min.3)Primary silicon in hypereutectic Al-25%Si alloy melt stirred by electromagnetism power moved generally with dauby liquid.Mechanical force, restraining anisotropic growth and aging effect will accelerate primary silicon to be fine or rotundity.4)For hypereutectic Al-Si alloy,the mechanical property of semi-solid metal sample is higher than that of metal mold sample because primary silicon turns to be smaller.