Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (4): 210-216.DOI: 10.13251/j.issn.0254-6051.2021.04.039

• TEST AND ANALYSIS • Previous Articles     Next Articles

Metallography technology of plasma sprayed Al2O3 ceramic coating

Xie Jing, Xie Shan, Quan Qiongrui, Li Xin   

  1. Metrology and Phy & Scem Center, AECC Aero Science and Technology Co., Ltd., Chengdu Sichuan 610503, China
  • Received:2020-10-17 Online:2021-04-25 Published:2021-05-08

Abstract: Metallographic sample preparation technology and microstructure evaluation technology of atmospheric plasma sprayed Al2O3 ceramic coating were studied by means of automatic metallographic sample preparation equipment and optical metallographic microscope, then the optimum sample preparation and evaluation methods were determined. The results show that by using resin bonded SiC wet grinding wheel cutting piece sampling, automatic grinding and polishing equipment equipped with correct specimen preparation parameters, SiC new sandpaper grinding and low resilience non wool cloth polishing, the true microstructure of the coating can be effectively revealed, and false images such as unreal abnormal large porosity can be avoided. The inherent angular morphology of Al2O3 powder produced by sintered fragmentation can be used for the evaluation of undissolved particles and remelted particles in the coating. As much as possibly reduced microscope aperture can be used to effectively distinguish the microstructure characteristics of the coating such as unmelted particles, remelted particles and oxides, etc.

Key words: plasma spraying, Al2O3 coating, microstructure, metallography, microscope aperture

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