https://scholars.lib.ntu.edu.tw/handle/123456789/74238
標題: | Processing and microstructure of Nano-Mo/Al2O3 composites from MOCVD and fluidized bed | 作者: | Lin, Ching-Jang CHIH-CHUNG YANG WEN-CHENG J. WEI |
公開日期: | 1999 | 卷: | 11 | 期: | 8 | 起(迄)頁: | 1361-1377 | 來源出版物: | Nanostructured Materials | 摘要: | The process utilizing metal-organic chemical vapor deposition (MOCVD) was conducted in a fluidized Al2O3 powder bed for the preparation of nano-Mo ceramic composites. During the process, Mo species were deposited in fine Al2O3 ceramic powder using a pyrolysis of Mo carbonyl. The composition and crystallinity of the intermediate phases of Mo2CxOy, and the microstructure of the coated particles and coated layer were analyzed using XRD/SEM/TEM techniques. The granulated powder was then treated by H2 reduction, pressureless sintering or hot-pressing in a vacuum, which could achieve densities better than 99% T.D. The densification, wear, and microstructural properties of the dense nano Mo-composites were then investigated and discussed. It is seen that the nano-inclusion of Mo grains inhibited the grain growth of the alumina matrix, which had a mean grain size of either 4.9 μm or 1.2 μm, as the volume fraction of Mo increased from 0 vol% to 5 vol%. The wear resistance of the nano-Mo/Al2O3 was approximately 2 times better than that of pure Al2O3. Through an understanding of the pyrolysis of Mo(CO)6 and grain growth kinetics of Mo-species growth kinetics, the morphology and size of the Mo grains in ceramic composites can be modified. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/95353 http://ntur.lib.ntu.edu.tw/bitstream/246246/95353/1/11.pdf https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033298947&doi=10.1016%2fS0965-9773%2800%2900433-5&partnerID=40&md5=cb80fcee893932b18cdbaf76f6edf765 |
ISSN: | 09659773 | DOI: | 10.1016/S0965-9773(00)00433-5 | SDG/關鍵字: | Alumina; Composition; Fluidized beds; Metallographic microstructure; Metallorganic chemical vapor deposition; Molybdenum; Pyrolysis; Reduction; Scanning electron microscopy; Sintering; Transmission electron microscopy; X ray diffraction analysis; Carbonyl; Intermediate phases; Nanostructured materials |
顯示於: | 材料科學與工程學系 |
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