The split of dendritic precipitates with interfacial anisotropy in solid transformations in alloys

Abstract

The dendritic precipitates may be obtained during isothermal treatment at the MSC temperature for a long time in solid transformations in the modeled alloy. The split of dendrite may occur while the temperature declines successively from the MSC point during quenching. The dendritic morphology is determined by the intensity of the interfacial anisotropy, and the split is related to the competition between the interfacial energy and the misfit strain energy. The doublet and octocube are possible while the dendritic particle is small, but if dendritic particle is large, the octodendrite may be obtained. The split of dendritic particles during aging is induced by the MSC effect which may be expressed by the MSC function which is determined by three parameters, the MSC rate β, the MSC delay t0 and the initial value of the MSC function α. The phase transformations during isothermal treatment at MSC point are spontaneous and equilibrium processes, however, phase transformations from MSC to the lower temperature during quenching are the spontaneous but non-equilibrium processes.