Secondary dendrite arm migration caused by temperature gradient zone melting during peritectic solidification

During dendritic solidification of Al-Ni and Sn-Ni peritectic alloys in a temperature gradient, it is observed that a thick peritectic layer forms on the front edge of the secondary dendrite arm of the primary phase, while there is almost no peritectic phase on the back edge. This observation is explained satisfactorily by a new version of secondary dendrite arm migration caused by temperature gradient zone melting during peritectic solidification, which involves both primary and peritectic phases. Experimental and theoretical analysis in the present work demonstrates that temperature gradient zone melting can cause extensive melting/solidification of the primary and peritectic phase during peritectic solidification.