高能等离子喷涂TBCs热循环失效机理研究

摘要

The powder beams of atmospheric plasma spraying and high energy plasma spraying had been studied, and Yttrium partially stabilized zirconia coatings (YSZ) were prepared by two kinds of processes. The microstructure of coatings during thermal cycling was studied to reveal the failure mechanism of TBCs. The results showed that:the velocity of the powder by high energy plasma spraying can reach up to 430m/s, while the APS is only 275m/s;bonding strength of coatings prepared by high energy plasma spraying is more than 60MPa and the APS is 45MPa;compared with APS, thermal cycling life of coatings prepared by high energy plasma spraying has been promoted up to 20%at least;the failure mechanisms of the two kinds of coatings are similar except that there is no fracture phenomenon happened in the coatings prepared by high energy plasma spraying.%本文研究了高能等离子喷涂和大气等离子喷涂两种工艺中粉末束流的特点，并采用两种喷涂工艺制备YSZ涂层，通过观察涂层在热循环条件下的微观组织变化，探讨了高能等离子喷涂YSZ涂层的热循环失效机理。结果表明，采用高能等离子喷涂工艺时，粉末粒子的速度可达430m/s，而采用常规大气等离子喷涂时，其速度仅为275m/s；采用高能等离子喷涂工艺制备的YSZ涂层的结合强度可大于60MPa，而大气等离子喷涂的YSZ涂层的结合强度为45MPa；与大气等离子喷涂相比，高能等离子喷涂工艺制备的YSZ涂层的热循环寿命可提高20%；在热循环过程中涂层内可形成垂直裂纹，但两种涂层的热循环失效方式相似。