Microstructural evolution and oxidation behaviour of Mo-Si-B coatings on an Nb-16Si-22Ti-7Cr-2Al-2Hf alloy at 1250 °C prepared by spark plasma sintering
Mo-Si-(5, 10, 15)B ternary coatings were firstly coated on an Nb-Si based alloy using the spark plasma sintering technique. The Mo-Si-B coatings consisted of an outer MoSi2/MoB/SiO2/Mo2B5 (Mo5Si3) layer and an inter-diffusion zone, while SiO2 was formed during SPS. The oxidation kinetics curves exhi...
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Published in | Surface & coatings technology Vol. 352; pp. 320 - 329 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Lausanne
Elsevier B.V
25.10.2018
Elsevier BV |
Subjects | |
Online Access | Get full text |
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Summary: | Mo-Si-(5, 10, 15)B ternary coatings were firstly coated on an Nb-Si based alloy using the spark plasma sintering technique. The Mo-Si-B coatings consisted of an outer MoSi2/MoB/SiO2/Mo2B5 (Mo5Si3) layer and an inter-diffusion zone, while SiO2 was formed during SPS. The oxidation kinetics curves exhibited parabolic time dependence and 5B coating had the lowest mass gain of approximately 0.41 mg/cm2 after oxidation at 1250 °C for 100 h. The good oxidation resistance results from a dense and protective borosilicate layer formed on coatings and the low growth rate of the inter-diffusion zone beneath the Mo-Si-B coatings.
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•SPSed Mo-Si-B coatings on Nb-Si substrate have an outer and an inter-diffusion layers.•Oxidation kinetics of the coatings obeys the parabolic law.•Mo-62Si-5B coating has the lowest mass gain oxidized at 1250 °C.•Good oxidation resistance results from a dense borosilicate layer.•Growth rate of inter-diffusion layer is dominated by diffusion of Si. |
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ISSN: | 0257-8972 1879-3347 |
DOI: | 10.1016/j.surfcoat.2018.08.027 |