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Abstract

The embodiments of the invention relate to a MoSi-SiC nanocomposite coating layer formed on surfaces of refractory metals such as Mo, Nb, Ta, W and their alloys. The MoSi-SiC nanocomposite coating layer is manufactured by forming a molybdenum carbide (MoC and MoC) coating layers on the surfaces of the substrates at high temperature, and the subsequent vapor-deposition of Si. The MoSi-SiC nanocomposite coating layer has a microstructure in which SiC particles are mostly located on the equiaxed MoSigrain boundary. The MoSi-SiC nanocomposite coating layer can have a close thermal expansion coefficient to that of the substrate by controlling a volume fraction of SiC particles exisiting in the nanocomposite coating. As a result, the generation of cracks due to the mismatch in the thermal expansion coefficients between the substrate and the nanocomposite coating layer is suppressed and the high-temperature repeated thermal cyclic oxidation resistance and the low-temperature oxidation resistance of the coated substrate are improved.