Spontaneous nucleation in hypoeutectic Al–Cu system by controlled diffusion solidification process

摘要: Controlled diffusion solidification (CDS) is a promising casting process. It involves the mixing of two precursor alloys that have different masses and temperatures. Small-sized globular grains appear in microstructure formed process, where grain refiner does not need to be added. Heterogeneous nucleation spontaneous occur during step. The heterogeneous occurs at crucible wall, while takes place supersaturated solution exposed high undercooling cooling rates established A one-dimensional model was built based on computational fluid dynamics technique numerically predict redistribution temperature solute model. two-step theory employed theoretically provide better understanding probability copious taking solution. results indicate strongly depends concentration alloys, thermal gradient between forming mixing, supersaturation parameter for CDS process compared with conventional process; show small size non-dendritic low superheat mixed happens from step numerical were validated experimental observations scanning electron microscopy.