The influence of electrical current on Al-Si alloys crystallization

This paper handles about the effect of electrical current on the cast microstructure of Al-Si alloy. By the application of direct current during the solidification there is intended the refinement of result microstructure. The change of result microstructure and mechanical properties was investigated. By the application of direct and alternating electrical current during the Al-Si alloy solidification there were observed some changes in the microstructure. The dendrites size in primary alpha phase was not been change markedly by the affect of electrical current. There was studied the size change of eutectic silicon on the samples. Eutectic silicon in the influenced sample is the same as eutectic silicon without electrical current application, only its length is shorter. Electromagnetical force activated by the transmission of electrical current flows into the increase of activating energy at the diffusion of silicon atoms and the silicon content inside the grains will be increased. By the application of electrical impulses of direct current the forces are influencing the hardening melt, which character is different as by the application of static electrical current.