Investigation of Compatibility Between M-Cr-Al-X Thermal Spray Coatings and Third Generation γ-TiAl Alloys
- 42 Downloads
In this work, the physical and chemical compatibility of cast Ti-Al-Nb-Cr-Zr and Ti-Al-Nb-Cr-Zr-B-La alloys was investigated with oxidation-resistant M-Cr-Al-X thermal spray coatings. Ti and Al are main alloy elements to form γ-TiAl and α2-Ti3Al phases. To obtain coatings, we used air plasma spray and high-velocity oxygen fuel equipment. Four commercially available M-Cr-Al-X powders, including Ta-containing, were used as starting materials. Our investigation of compatibility between M-Cr-Al-X thermal spray coatings and γ-TiAl alloys consists of isothermal annealing in air muffle furnace during 100 h at 920 °C, followed by samples investigation. Oxidation products formed at coatings surface were studied by XRD analysis with Rietveld refinement. Interdiffusion between coatings and alloys was studied by means of cross-sectional SEM with EDX analysis. Plots were made to show concentration of each main element at the end of experiments. Samples were subjected to dynamic mechanical thermal analysis in order to determine the effect of high-temperature exposure on complex elastic modulus. Finally, burner rig cycling test was performed to estimate the thermal shock resistance of M-Cr-Al-X coatings.
Keywordsγ-TiAl alloy aluminum MCrAlY coatings oxidation phase composition titanium thermal spray
This work was supported by government contract No 11.1934.2017/ПЧ dated 31.05.2017. Additional support was provided through the European Research Council under the ERC Advanced Grant INTELHYB, Grant Number: ERC-2013-ADG-340025.
- 22.S. Saeidi, Microstructure, Oxidation & Mechanical Properties of As-Sprayed and Annealed HVOF & VPS CoNiCrAlY Coatings, Doctoral Dissertation. UK: University of Nottingham, 2010Google Scholar