China's Refractories

《中国耐火材料》英文版

China's Refractories ›› 2025, Vol. 34 ›› Issue (3): 24-29.DOI: 10.19691/j.cnki.1004-4493.2025.03.004

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Process and Bonding Performance of ZrO2 Thermal Barrier Coatings with Dense Vertical Cracks by High Energy Plasma Spray

YANG Qinqian1,2, NIU Yunsong1,3,*, HUANG Di1,2, BAO Zebin1,2, ZHU Shenglong1,2   

  1. 1 Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
    2 School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China;
    3 State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
  • Online:2025-09-15 Published:2025-09-24
  • Contact: *e-mail: ysniu@imr.ac.cn
  • About author:Yang Qinqian is a doctoral candidate of the University of Science and Technology of China. His research fields cover the design method of high-temperature protective coatings, focusing on the design research of ceramic thermal barrier coatings for gas turbines/aero-engines. At present, he has made significant progress in the research of 8YSZ and other multiphase coatings, improving the sintering resistance and mechanical properties of YSZ coatings and delaying the growth of TGO.

Abstract: In order to prolong the service life of ZrO2 thermal barrier coatings, HS188 alloy was used as the substrate, and NiCrAlY powder (base layer, d50=106 μm) and yttria stabilized zirconia (YSZ, d50=50 μm) were employed as the sprayed feeder to prepare NiCrALY+YSZ thermal barrier coatings using high-energy plasma spraying equipment with a progressive exploration method. The microstructure of the coatings was controlled by adjusting the stand-off distance (85, 95, 105 and 115 mm) and air-cooling manner (rear air cooling, rear air cooling + gun cooling, front air cooling, and front air cooling + gun cooling). The bonding strength of the coatings was evaluated by the drawing method. The results indicate that under the conditions of long stand-off distance and low cooling rate, it is difficult for the coatings to form a vertical crack structure due to the low instantaneous heating temperature and insufficient quenching on the sample surface. However, when the instantaneous heating temperature reaches the critical value and the air cooling rate is excessive, un-melted spray particles exist. When the stand-off distance is 85 mm and the cooling method is front air cooling, a thermal barrier ceramic coating with vertical crack morphology was obtained on HS188 alloy. Simultaneously, it has a moderate density of vertical cracks, the highest bonding strength and the best toughness.

Key words: high-energy plasma spraying, thermal barrier coating, stand-off distance, air-cooling, bonding strength