The influence of surface roughness of sprayed zirconia coatings on laser treatment
The influence of surface roughness of sprayed zirconia coatings on laser treatment
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DOI：
10.1016/s0257-8972(01)01325-1
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发表时间：
2001-11
影响因子：
5.4
通讯作者：
S. Chwa;A. Ohmori
中科院分区：
文献类型：
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作者：
S. Chwa;A. Ohmori
研究了等离子喷涂氧化锆涂层表面粗糙度对激光后处理的影响。为了减小普通光学系统获得的非均匀激光束对涂层激光处理的影响，对传统的YAG激光枪进行了改造，通过安装万花筒获得了强度均匀的激光束。抛光涂层的熔融深度约为接收态涂层的熔融深度的一半，即使在相同的功率密度（38.4 W/mm 2）下处理时也是如此，并且接收态涂层和抛光涂层之间的熔融深度的这种差异随着功率密度（47.9 W/mm 2）而增加。在具有粗糙表面的喷涂涂层的情况下，根据功率密度，不均匀和粗糙处理的区域急剧增加。与抛光涂层（Ra，0.27 μ m）相比，表面粗糙度为Ra，4.7 μ m的涂层的漫反射率有所增加，在Nd/YAG激光波长（1016 nm）附近，喷涂涂层和抛光涂层的漫反射率相差约10%。在本实验中，激光处理后，未观察到单斜相的出现，而非相变的t′相仍占主导地位。
The influence of surface roughness of plasma sprayed zirconia coatings on post-laser treatment was investigated. To minimize the influence from the non-uniform laser beams obtained through the usual optics on the laser treatment of coatings, a conventional YAG laser gun was modified, and laser beams with a uniform intensity were obtained by installing the kaleidoscope. The melted depth of the polished coatings was approximately half that of as-received coatings even when treated at the same power density (38.4 W/mm2) and this difference of melted depth between the as-received coatings and polished coatings increased with the power density (47.9 W/mm2). In the case of as-sprayed coatings with a rough surface, uneven and roughly treated areas were sharply increased in accordance with the power density. As-received coatings with surface roughness (Ra, 4.7 μm) showed an increased diffuse reflectance compared with polished coatings (Ra, 0.27 μm), and the difference in reflectance between the as-sprayed and polished coatings was approximately 10% near the wavelength of the Nd/YAG laser (1016 nm). In this experiment, the appearance of the monoclinic phase, one of the important indicators determining the stability of TBC coating, was not observed and non-transformable t′ phase was still predominant after laser treatment.