论文部分内容阅读
采用区域重熔定向凝固技术制备了Ti-45Al合金定向凝固试样,研究了不同参数下的凝固组织。结果表明,该合金在定向凝固过程中一次凝固可以以胞晶形式实现定向生长,胞晶内α2/γ片层方向与生长方向成45°或90°。凝固过程中稳定相β及亚稳相α同时存在,并以胞状生长,存在竞争而引起的交替现象。降速生长时定向组织比较理想。淬火实验表明,在大过冷度下亚稳α相作为领先相析出。
The directional solidification samples of Ti-45Al alloy were prepared by the zone remelting directional solidification technique, and the solidified structures under different parameters were studied. The results show that the first solidification during directional solidification can achieve directional growth in the form of cell crystal. The direction of α2 / γ lamellae in the intragranular is 45 ° or 90 ° with the growth direction. In the process of solidification, the stable phase β and the metastable phase α coexist and grow in a cell-like form with the alternation caused by competition. Directional tissue growth is more ideal when it is slowed down. Quenching experiments show that metastable α phase is precipitated as the leading phase under the condition of large undercooling.