Fabrication of Aluminum Nitride Coating by Reactive RF Plasma Spraying
Fabrication of Aluminum Nitride Coating by Reactive RF Plasma Spraying
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反应性射频等离子喷涂氮化铝涂层的制备
DOI：
10.2207/qjjws.23.143
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Koyata Takahashi
中科院分区：
文献类型：
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作者：
M. Yamada;Hajime Nakamura;M. Fukumoto;T. Yasui;Koyata Takahashi
氮化铝（AlN）因其优异的化学稳定性和导热性而成为备受关注的表面改性陶瓷之一。通常，薄AlN涂层是通过CVD或PVD工艺制造的。然而，这些工艺无法产生可能有助于结构部件的厚涂层，因为这些工艺中的沉积速率相当低。通过热喷涂工艺可以轻松获得厚涂层。然而，由于AlN在2273K时会分解，采用传统热喷涂法制备AlN涂层相当困难。在本研究中，AlN 涂层是通过反应射频 (RF) 等离子喷涂制备的。反应性等离子喷涂工艺，其中金属元素与等离子体中周围的活性物质发生反应，对于非氧化物陶瓷的喷涂是有效的。射频等离子体由于其低流速和高能量，可以为单质金属提供足够的反应机会。通过提高等离子气体中的氮含量，获得了不含纯Al相的AlN涂层，但涂层微观结构不均匀、脆性且多孔。另一方面，通过降低等离子气体中的氮含量，可以获得具有更均匀、更少孔隙微观结构的Al/AlN复合涂层。改变等离子气体中的氮含量可能有效控制Al/AlN复合涂层中的AlN含量。
Aluminum nitride (AlN) is one of the attractive ceramics applicable to the surface modification because of its excellent properties in chemical stability and thermal conductivity. Generally, thin AlN coatings are fabricated by CVD or PVD process. However, these processes cannot produce thick coatings, which might contribute to the structural parts, because of quite low deposition rate in these processes. Thick coatings can be easily given by thermal spray process. However, fabrication of AlN coating by conventional thermal spraying is fairly difficult due to decomposition of AlN at 2273K. In this research, AlN coating was fabricated by reactive Radio Frequency (RF) plasma spraying. Reactive plasma spray process, in which metal element reacts with surrounding active species in plasma, is effective for the spraying of non-oxide ceramics. RF plasma can offer the enough reaction chance to the elemental metal because both of its low flowing velocity and high energy. By increasing nitrogen content in plasma gas, AlN coating without pure Al phase was attained while the coating microstructure was heterogeneous, brittle and quite porous. By decreasing nitrogen content in plasma gas, on the other hand, Al/AlN composite coating with more homogeneous, less porous microstructure could be attained. Changing nitrogen fraction in plasma gas may be effective for controlling AlN content in Al/AlN composite coating.