Journal of Thermal Spray Technology

, Volume 20, Issue 6, pp 1201–1208 | Cite as

Preparation and Thermophysical Properties of La2Zr2O7 Coatings by Thermal Spraying of an Amorphous Precursor

Peer Reviewed

Abstract

Free-standing La2Zr2O7 coatings were obtained by plasma spraying, using an amorphous La-O-Zr precursor as the feedstock. The La-O-Zr precursor powder was prepared by coprecipitation. During thermal spraying, the formation of coatings can be regarded as a joint process of melting-solidification, thermal decomposition, and crystallization. The time required for crystal growth was significantly shortened during spraying. Consequently, the average grain size of coatings was approximately 200 nm, with a narrow distribution (100-500 nm). Coatings prepared by this method show better thermophysical properties than those prepared with crystalline La2Zr2O7 powder as the feedstock. The thermal conductivity of the as-sprayed coating was approximately 0.36-0.47 W/m K and the average coefficient of thermal expansion (CTE) is 11.1 × 10−6/K.

Keywords

amorphous powder feedstock lanthanum zirconate plasma spraying thermal barrier coating thermophysical property 

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Copyright information

© ASM International 2011

Authors and Affiliations

  1. 1.State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics (SIC)Chinese Academy of Sciences (CAS)ShanghaiChina
  2. 2.Graduate University of Chinese Academy of SciencesBeijingChina
  3. 3.The Key Laboratory of Inorganic Coating Materials, Shanghai Institute of CeramicsChinese Academy of SciencesShanghaiChina

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