Competitive growth of high purity aluminum grains in directional solidification
(1.上海市上海交通大学金属基复合材料国家重点实验室
2.State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University,Shanghai 200030, China
3.Analysis and Testing Center for Inorganic Materials, Shanghai Institute of Ceramics,Chinese Academy of Sciences, Shanghai 200037, China)
2.State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University,Shanghai 200030, China
3.Analysis and Testing Center for Inorganic Materials, Shanghai Institute of Ceramics,Chinese Academy of Sciences, Shanghai 200037, China)
Abstract: A self-made directional solidification setup was used to prepare high purity aluminum ingots of 100mm in diameter. The morphology of the growth interface was detected by SEM and AFM, and the grain lattice orientation was detected by XRD. The results indicate that the grains suffer competitive growth under any conditions in experiments. The lattice orientation of the preferred grains is determined by the flow field above the solid-liquid interface. The horizontal lattice position does not change during the growth process. However, the lattice orientation in the growth direction varies with the growth velocity and approaches to [100] gradually during the growth process.
Key words: high purity aluminum; competitive growth; directional growth; lattice orientation