The effect of a novel low-voltage alternating current pulse(ACP)controlled by transformer and silicon controlled rectifier on the solidification structure of Al-20%Si alloy was investigated.The results indicated that ...The effect of a novel low-voltage alternating current pulse(ACP)controlled by transformer and silicon controlled rectifier on the solidification structure of Al-20%Si alloy was investigated.The results indicated that the remarkable segregation of primary Si occurred during the solidification,and even dendrites of a-Al phase appeared at the center of samples under ACP.The thickness of segregation layer decreased first and then increased with current density increasing from 0 to 300 Acm^(-2).The primary Si existed with long pole or five petal star-shaped without ACP.However, the morphology of primary Si phases changed to block under ACP,and the sizes of blocky Si decreased obviously with increasing current density from 110 to 300 Acm^(-2).The formation mechanism of the structure of hypereutectic AI-20%Si alloy was also discussed under ACP.展开更多
基金Item Sponsored by NPU Foundation for Fundamental ResearchChina[Grant No.JC201272]
文摘The effect of a novel low-voltage alternating current pulse(ACP)controlled by transformer and silicon controlled rectifier on the solidification structure of Al-20%Si alloy was investigated.The results indicated that the remarkable segregation of primary Si occurred during the solidification,and even dendrites of a-Al phase appeared at the center of samples under ACP.The thickness of segregation layer decreased first and then increased with current density increasing from 0 to 300 Acm^(-2).The primary Si existed with long pole or five petal star-shaped without ACP.However, the morphology of primary Si phases changed to block under ACP,and the sizes of blocky Si decreased obviously with increasing current density from 110 to 300 Acm^(-2).The formation mechanism of the structure of hypereutectic AI-20%Si alloy was also discussed under ACP.
