单晶高温合金晶体取向的研究进展

单晶高温合金晶体取向与轴向的偏离已成为单晶叶片的一个重要缺陷.简述了单晶生长过程中在不同界面形态下择优取向的转变规律,以及取向对枝晶形貌和尺度的作用;分析了不同取向晶粒的竞争机制,并展望了晶体取向今后研究发展方向;指出了温度梯度、界面形状、熔体等是影响单晶高温合金晶体择优取向的重要因素.

Research Progress in Crystal Orientation of Single Crystal Superalloys

The deviation of preferred orientation of single crystal superalloys from the axis is one of the most important defects. In this paper, the conversion rule of preferred orientation during the process of the crystal growth is introduced briefly, and the same time, the effects of the orientation on the dendritic morphology and scale are studied. The competitive principles of grains with different crystal orientations are also analyzed, and the suggestions are pointed out for further consideration. The influence factors for the preferred orientation are summaried, such as the growth methods, temperature gradient, the shape of the interface, melt and so on.