Microstructural analysis of Ta-containing NiCoCrAlY bond coats deposited by HVOF on different Ni-based superalloys

SURFACE & COATINGS TECHNOLOGY

卷:354

Article

Mora-Garcia, A. G.^1,3  Ruiz-Luna, H.²  Mosbacher, M.³  Popp, R.³  Schulz, U.⁴  Glatzel, U.³  Munoz-Saldana, J.^1,4 

[1] Ctr Invest & Estudios Avanzados, IPN Unidad Queretaro, Libramiento Norponiente 2000, Queretaro 76230, Mexico

[2] Univ Autonoma Zacatecas, Conacyt, Av Ramon Lopez Velarde 801, Zacatecas 98000, Mexico

[3] Bayreuth Univ, Inst Met & Alloys, Ludwig Thoma Str 36b, D-95447 Bayreuth, Germany

[4] Inst Mat Res, German Aerosp Ctr, Linder Hohe, D-51147 Cologne, Germany

关键词: Ta-containing NiCoCrAlY coating;    HVOF deposition;    Ni-based superalloys;    Elemental diffusion;   

DOI  :  10.1016/j.surfcoat.2018.09.025

来源: Elsevier

【 摘 要 】

The microstructural and chemical evolution after different processing steps of Ta-containing NiCoCrAlY bond coats (BC) sprayed by high velocity oxy-fuel on Ni-base superalloy (SA) substrates, top-coated with 7YSZ and furnace cycled at 1100 degrees C focusing along the BC/SA interfaces is presented. Three superalloys were selected considering their Ta content relative to that within the BC: a) no Ta in the superalloy composition (IN100) and either b) similar or c) higher Ta content with respect to the BC (M247LC SX and CMSX-4, respectively). The processing conditions were as-sprayed, as-annealed, after EB-PVD deposition of a 7YSZ top coat, and after furnace cyclic tests (1100 degrees C/120 h). The evolution of chemical composition after the different process steps are presented that include a normalization criteria to a Ni-Al-Cr system, elemental profiles as well as Weibull distribution plots of minor containing elements such as Ti, Ta, Mo, or W at the BC/SA interface. The effect of Ta was activated in some coated substrates by the presence of Ti and C in the superalloy consisting of inward Tadiffusion, trapping of outward diffusing Ti and the subsequent formation of (Ta, Ti)-rich carbides in the BC avoiding possible segregation effects as titanium oxide in the oxide scale.

【 授权许可】

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