( 1. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院， 哈爾濱 150001;
2. 西安理工大學(xué) 材料科學(xué)與工程學(xué)院， 西安 710048)
摘 要: 采用常流脈沖控制方式于(NaPO3)6-NaF-NaAlO2溶液中用微弧氧化法在Ti6Al4V表面制備了陶瓷化涂層， 研究了涂層的生長過程及組織結(jié)構(gòu)變化。結(jié)果表明： 氧化過程中涂層的生長經(jīng)歷了由快到慢的過程， 在前10min涂層以較快速度生長（約3μm/min）， 隨著時(shí)間的延長涂層生長速度逐漸減慢； 生長過程中涂層表面微孔數(shù)目減少，微孔孔徑增大， 涂層表面氣孔率增大； 涂層主要由二氧化鈦的兩種不同變體（銳鈦礦及金紅石）以及磷化物相AlPO4組成； 隨著氧化的進(jìn)行， 銳鈦礦含量降低，金紅石含量增加， 氧化過程中發(fā)生了銳鈦礦相到金紅石相的相轉(zhuǎn)變； 結(jié)晶AlPO4相是通過水合多聚磷酸鋁在放電區(qū)附近發(fā)生高溫?zé)峤夥磻?yīng)而進(jìn)入涂層。
關(guān)鍵字: 鈦合金； 微弧氧化； 涂層生長； 組織結(jié)構(gòu)
（ 1. School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 150001, China;
2. School of Materials Science and Engineering,
Xi′an University of Technology, Xi′an 710048, China）
Abstract: Ceramic coatings were fabricated by microarc oxidation method with a control mode of constant current density on Ti6Al4V alloy in(NaPO3)6-NaF-NaAlO2 solution. The growth process and microstructure variation of microarc oxidation coatings were investigated. The results show that the coatings growth rate is subjected to a variation from rapidness to tardiness during the process. The coating grows rapidly with a rate of approximate 3μm/min within the initial time period of 10min, and followed by a gradually decreasing rate in the later treatment. With increasing treatment time, the micropores number on the surface of the coatings decreases obviously, while the size of micropores increases, as a result, the porosity increases. The coatings are mainly composed of the two modifiers of titanium oxide(namely anatase and rutile) and AlPO4. As the treatment time increases, the anatase content decreses, and the rutile content increases, which indicates that the phase transformation of anatase into rutile occurs during the oxidizing process. The crystalline AlPO4 involves the coatings via high-temperature thermolysis of hydrated aluminium polyphosphates in the near channel zone of microdischarging.
Key words: titanium alloy; microarc oxidation; coatings growth; microstructure
