Yoon, Jin-Kook Son, Keun-Hyung Han, Jun-Hyun Kim, Gyeung-Ho Doh, Jung-Mann Hong, Kyung-Tae 2024-01-21T05:32:51Z 2024-01-21T05:32:51Z 2021-09-01 2005-03 0044-3093 https://pubs.kist.re.kr/handle/201004/136725 The microstructures and formation processes of MoSi2-Si3N4 or MoSi2-SiC nanocomposite coatings on Mo substrates by ammonia nitridation or carburizing process followed by chemical vapor deposition of Si was investigated using optical microscopy, field-emission scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (XTEM), and X-ray diffraction (XRD). The present study demonstrated that the crack density formed in the MoSi2-base nanocomposite coatings due to mismatch in the coefficient of thermal expansion (CTE) between the nanocomposite coatings and the Mo substrate could be reduced by the control of volume percentage of the Si3N4 or SiC particles with the low CTE values. Especially, no cracks were observed in the MoSi2-(30-33) vol.% Si3N4 nanocomposite coating, indicating that its CTE value was close to that of the Mo substrate. The microstructure of MoSi2-base nanocomposite coatings showed the oblatespheroidal-type Si3N4 or SiC particles dispersed in the equiaxed MoSi-, grains. The average size of equiaxed MoSi2 grains ranged from 300 to 100 nm depending on the processes, and that of Si3N4 or SiC particles ranged from 150 to 90 nm. The growth of MOSi2 grains was inhibited by the nanosize Si3N4 or SiC particles located mostly at the grain boundaries of MoSi2. English Hanser Publishers Microstructure of MoSi2-base nanocomposite coatings formed on Mo substrates by chemical vapor deposition Article 10.3139/146.101032 1 Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques, v.96, no.3, pp.281 - 290 Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques 96 3 281 290 N scopus 000228395200010 2-s2.0-16244401990 Metallurgy & Metallurgical Engineering Metallurgy & Metallurgical Engineering Article; Proceedings Paper STATE DISPLACEMENT REACTION MECHANICAL-PROPERTIES GROWTH-KINETICS THIN-FILMS COMPOSITES MOLYBDENUM SILICON TEMPERATURE DIFFUSION ALLOYS CVD MoSi2-base nanocomposite coating microstructure molybdenum