Comparison of microstructure and oxidation behavior of CoNiCrAlY bond coatings prepared by different thermal spray processes

Mitsuhiro Shibata, Seiji Kuroda, Hideyuki Murakami, Machiko Ode, Makoto Watanabe, Yukihiro Sakamoto

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

To protect various gas turbine components against high temperature in the hot sections of power generation plants and aircraft engines, thermal barrier coatings (TBCs) have been developed and widely used. Conventional TBCs consist of a MCrAlY bond coating for oxidation resistance and a ceramic top coating for thermal insulation. High quality coatings of MCrAlYs have been produced mostly by low pressure plasma spraying but other more economical processes are also used depending on the operating conditions of the component to be coated. In this study, CoNiCrAlY powders were deposited on Inconel 718 substrate with 3 types spraying system, i.e., low pressure plasma spraying, high velocity oxy-fuel spraying, and atmosphere plasma spraying. The specimens without top ceramic coating were isothermally tested for up to 100hrs in air at 1373 K and mass gain of the coatings was measured. Microstructure of the coating cross sections and the surface oxides were observed with SEM. Moreover, phase changes during the oxidation test were investigated with calculated phase diagrams for the CoNiCrAlY alloy.

Original languageEnglish
Pages (from-to)1638-1642
Number of pages5
JournalMaterials Transactions
Volume47
Issue number7
DOIs
Publication statusPublished - 2006 Jul 1
Externally publishedYes

Keywords

  • Bond coating
  • CoNiCrAlY
  • High temperature oxidation
  • High velocity oxy-fuel spray
  • Low pressure plasma spray
  • Phase diagram
  • Thermal barrier coating

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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