Ti-6Al-4V在NaAlO_2溶液中微弧氧化陶瓷膜的组织结构研究

Microstructure of Ceramic Coatings Formed on Ti-6Al-4V Alloy by Microarc Oxidation in NaAlO_2 Solution

利用交流微弧氧化方法在NaAlO2 溶液中在Ti- 6Al- 4V合金表面制备出氧化物陶瓷膜 ,用扫描电镜及能谱仪研究了陶瓷膜的形貌、组织和Ti、Al、O元素的分布 ,并用X射线衍射分析了陶瓷膜的相组成 .所制备的陶瓷膜与基体界面结合良好 ,膜厚约 5 0微米 ,分为内外两层 .外层膜由大量TiAl2 O5相及少量金红石型TiO2 相组成 .内层膜的TiAl2 O5相含量显著降低 ,金红石则成为主体相 ,同时还发现少量TiO1.9相 .这些相都是由微弧区熔融物快速冷却形成的 .微弧区高温高压过程没有改变膜 /基体界面附近的合金基体组织 .

Describle the ceramic oxide coating prepared on Ti-6Al-4V alloy by AC microarc oxidation in NaAlO 2 solution and its morphology and microstructure observed using Scanning Electron Microscope (SEM); the analysis of composition profiles of Ti, Al, O elements in the coatings using Energy Dispersive Spectroscope (EDS), and the phase constituent of the coatings determined using X ray diffraction (XRD) and points out the ceramic coating with about 50 μm thickness contains two layers, an outer layer and an internal layer, and the outer layer is composed of a large amount of TiAl 2O 5 phase and a little rutile type TiO 2 phase, but, in the internal layer, rutile becomes a main phase while the TiAl 2O 5 content obviously decreases and a little TiO 1.9 phase also appears in the internal layer, and all of these phases derive from rapid solidification of the molten coatings in the microplasma discharge zone, and the high temperature and pressure processes have hardly influenced on the substrate microstructure near the coating/substrate interface.