The Isothermal Oxidation of MCrAlY Protective Coatings

Abstract

The thermal barrier coatings (TBC) are commonly used for protection of jet engine parts. In presented article the influence of chemical composition of TBCs bond coats on isothermal oxidation resistance was analysed. The bond coat was plasma sprayed (APS) using different MCrAlY alloys produced by Oerlikon-Metco: Metco 4451, AMDRY 997, AMDRY 962, AMDRY 365-1, AMDRY 995C. The conducted research showed big difference in coating thickness despite the same spraying parameters. The difference in porosity was not observed. The isothermal oxidation test was conducted during 500h at 1100°C in static laboratory air. The obtained results showed, that degradation mechanism of MCrAlY bond coats regardless of chemical composition is similar. The formation of scale contained aluminium and chromium oxides was observed. The internal oxidation effect was also observed in produced coatings.

The Oxidation Properties of a NiCrAlY Coating Fabricated by Arc Ion Plating

“…The Al 2 O 3 scale is not only able to isolate corrosive media from the coating and superalloy, but also is very stable and an excellent protective scale at high temperature. Among all kinds of high-temperature protective coatings, MCrAlY (M = Ni, Co, or Ni and Co) coating can be adopted as a standalone coating and as the bond coating of thermal barrier coatings (TBCs) [4][5][6][7][8]. For the MCrAlY coating, M is the main element, which is used to match with the substrate superalloy; Al is oxidized to Al 2 O 3 , whose content is about 7-16 wt.%; Cr, with a content of 15-35 wt.%, improves the corrosion resistance of the coating.…”

Thermal Spraying of MCrAlY Overlay Coating Using New Ethanol-Fueled HVOF Gun

“…It was successfully tested for deposition of tungsten-carbide coatings [11] with similar to conventional HVOF-gun sprayed coatings. In our previous researches we established the MCrAlY coating spraying parameters using low pressure plasma spraying (LPPS) [12,13] and conventional APS processes [14]. In present article the process parameter for NiCoCrAlY coatings production using newly developed ethanol-based HVOF process were investigated.…”