复合工艺制备的半固态A356铝合金初生相形貌分形特征研究

利用复合工艺制备了A356铝合金半固态浆料，研究了半固态A356铝合金初生相形貌的分形特征．应用编制的计算程序计算了半固态A356铝合金初生相形貌的分形维数．结果表明，复合工艺制备的半固态A356铝合金初生相的形貌可以用分形维数来表征，不同工艺参数下所获得的半固态初生相形貌具有不同的分形维数．铸锭中不同部位半固态初生相的形貌具有不同的分形维数，反映了同一铸锭不同部位的凝固条件对半固态初生相形貌的影响．凝固组织中的每个半固态初生相的分形形貌均为系统耗散性的几何表现．

Research on Fractal Characteristic of Primary Phase Morphology in Semi-solid A356 Alloy Prepared by Compound Process

Semi-solid slurry of A356 alloy is prepared by compound process, and the fractal characteristic of morphology in semi-solid primary phase is studied. The fractal dimensions of primary phase morphology in semi-solid A356 alloy are calculated by the calculating program written to calculate the fractal dimensions of box-counting in the imagine of morphology of semi-solid primary phase in A356 alloy. The results indicate that the morphology of primary phase in semi-solid A356 prepared by compound process is characterized by fractal dimension, and the morphology of primary phase prepared by the different technology parameters has different fractal dimensions. The morphology of primary phase at the different positions of ingot has different fractal dimensions, which reflecte the effect of solidified conditions at different positions in the same ingot on the morphology of semi-solid primary phase. All fractal morphology for each semi-solid primary phase in solidified microstructure is the geometric expression of dissipativity in the system.