Numerical Simulation On The Solidification Processing During Aluminum Continuous Cast-Rolling Process

Twin-roll strip casting is thought as a potential technology in the field of metallurgy and materials. It has been found that the main problem of its industrializaion application, is that the quality of aluminium strip is poor and unstable. Since the solidification structure of thin strip has great effect on the strip quality, it is very necessary to investigate the influence of the processing parameters on the solidification structure of thin strips. Considering that the relationship among these processing parameters is very complicated, the experimental investigation would be very hard and difficult. In order to solve this problem, the numerical simulation is used in this paper, by which the research work can be obviously simplified. Because the processing performance and final properties of thin strip are affected by the distribution feature of the crystal zones and the three-dimensional size of the crystal grains in different crystal zones, it is also very important to carry out the investigation on parameter description of the solidification structure of twin-roll thin strips.The basic theory of heat transfer with the property of material [liquid-solid] rheologic shaped on the basis of summarizing the developing status of cast-rolling technology was connected in this paper. It was researched that the heat transfer mechanism of shaped interface and the system heat transfer regular under the multi-coupling mechanism and the heat transfer property of shaped interface based on the high grad of change of temperature. In addition, the heterogeneous nucleation model and the competition growth mechanism between columnar dendrite and equiaxed dendrite were introduced, together with the revising of the dynamic model, KGT model, which was originally established under the pure diffusion condition to simulate the dendrite tip growth during the rapid solidification process. Since the solid fraction is expressed as the function of nucleation density and growth velocity and is not treated as the function of temperature in this model, the coupling between solidification thermodynamics and crystallization kinetics during the solidification process of twin-roll thin strip can be realized truly.