Influence of heat treatment on nanocrystalline zirconia powder and plasma-sprayed thermal barrier coatings

• Published in: Transactions of Nonferrous Metals Society of China Vol. 20; no. 12; pp. 2272 - 2280
• Main Author: 蒋显亮 刘纯波 刘敏 朱晖朝
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2010; School of Materials Science and Engineering, Central South University, Changsha 410083, China%Guangzhou Research Institute of Non-ferrous Metals, Guangzhou 510651, China
• Subjects: Calcination; Deposition; Heat treatment; nanocrystalline material; Nanostructure; phase composition; Phases; Sprays; thermal barrier coating; Thermal barrier coatings; zirconia; Zirconium dioxide; 低压等离子喷涂; 氧化锆粉末; 热障涂层; 焙烧温度; 空气等离子喷涂; 纳米氧化锆; 纳米结构; 高温热处理; thermal barrier coating; phase composition; zirconia; heat treatment; nanocrystalline material
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(10)60640-1

Nanostructured zirconia top coat was deposited by air plasma spray and NiCoCrAlTaY bond coat was deposited on Ni substrate by low pressure plasma spray.Nanostructured and conventional thermal barrier coatings were heat-treated at temperature varying from 1050 to 1 250oC for 2-20 h.The results show that obvious grain growth was found in both nanostructured and conventional thermal barrier coatings（TBCs）after high temperature heat treatment.Monoclinic/tetragonal phases were transformed into cubic phase in the agglomerated nano-powder after calcination.The cubic phase content increased with increasing calcination temperature.Calcination of the powder made the yttria distributed on the surface of the nanocrystalline particles dissolve in zirconia when grains grew.Different from the phase constituent of the as-sprayed conventional TBC which consisted of diffusionlesstransformed tetragonal,the as-sprayed nanostructured TBC consisted of cubic phase.