激光改性对YSZ涂层结构与性能的影响

The influence of laser treatment on the microstructure and properties of YSZ thermal barrier coatings

摘要:

本文采用电子束物理气相沉积技术在Ni基单晶基体表面制备双层结构的热障涂层后,采用脉冲Nd:YAG激光对其进行激光表面改性处理,获得具有复合陶瓷层结构的热障涂层。然后,对改性前后试样进行了1100℃高温氧化处理,并采用SEM和XRD分析了激光改性对涂层微观形貌和组织结构,以及抗氧化性能和耐腐蚀性能的影响。结果发现：激光改性处理后,试样表面形成致密平整的重熔层组织,该组织与原柱状晶组织共同构成了复合结构的陶瓷层,复合结构的陶瓷层减缓了有害元素向基体的扩散行为,提高了涂层的抗氧化性能和耐腐蚀性能。

Abstract:

In this paper, electron beam physical vapor deposition technique was taken to prepare double structure thermal barrier coatings on Ni-based single crystal substrate. Then, a Nd: YAG laser was used to modify the surface of the as-deposited samples to obtain a thermal barrier coatings with a composite structure. The oxidation resistance and corrosion resistance of EB-PVD deposited as well as laser-modified coatings were investigated by isothermal oxidation treatment at 1100℃. The microstructure and phase composition of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The results revealed that the surface of the coating formed a dense layer after the laser modifing, which structure was together with the original columnar crystals YSZ layer, deposited by EB-PVD, to a composite ceramic coating. Consequently, the diffusion behavior of harmful element was slowed down by composite ceramic coating into the substrate, and the oxidation resistance and corrosion resistance of the samples were improved.