摘要 :
Multilayer alumino-silicide and silicide coatings were formed by in situ chemical vapour co-deposition of Al and Si on TZM (Mo-0.5Ti-0.1Zr-0.02C) alloy for improving its high-temperature oxidation resistance. MoSi_2 and Mo (Si, Al...
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Multilayer alumino-silicide and silicide coatings were formed by in situ chemical vapour co-deposition of Al and Si on TZM (Mo-0.5Ti-0.1Zr-0.02C) alloy for improving its high-temperature oxidation resistance. MoSi_2 and Mo (Si, Al)_2 layers were formed in the inner and the outer layers, respectively in the case of alumino-silicide coating. Whereas silicide coating consisted of Mo_5Si_3 and MoSi_2 phases in the inner and the outer layers, respectively. 24-100-μm thick coatings were formed by optimizing the pack mixture of Al and or Si, NH_4F and Al_2O_3 powders and conducting the experiments at 1000 ℃ for 8-36 h. MoSi_2 layer showed a faster growth rate and presence of columnar grains. A small weight gain at the initial stages was observed during the oxidation tests of the coated samples under continuous or cyclic heating at 1300 ℃ in air. Neither cracks nor peeling of the coating layers were noticed after oxidation tests.
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