(1. 四川理工學(xué)院 材料科學(xué)與工程學(xué)院，自貢 643000；
2. 四川理工大學(xué) 材料腐蝕與防護(hù)四川省重點(diǎn)實(shí)驗(yàn)室，自貢 643000)
摘 要: 通過微弧氧化和多弧離子鍍兩種等離子體技術(shù)，在AZ31B鎂合金表面制備MAO/Ti復(fù)合涂層。采用SEM、EDS、XRD、電化學(xué)等手段表征涂層的形貌、元素組成、物相結(jié)構(gòu)及其在3.5% NaCl(質(zhì)量分?jǐn)?shù))溶液中的腐蝕行為。結(jié)果表明：隨著磁場電流從0 A增加到20 A， 30 min沉積的MAO/Ti涂層表面大尺寸熔滴粒子數(shù)量逐漸減少，真空室溫度由128 ℃增加到192 ℃；10 A磁場電流作用下，當(dāng)沉積時間由30 min延長到120 min時，真空室溫度迅速增加，MAO/Ti涂層表面呈現(xiàn)微裂紋，表面液體熔滴粒子的數(shù)量增加；無外加磁場時，隨著沉積時間從30 min延長到120 min，MAO/Ti涂層表面呈現(xiàn)大量球形熔滴顆粒，Ti鍍層厚度逐漸增加并完全覆蓋MAO膜；多弧離子鍍過程未改變MAO鎂合金的主要物相結(jié)構(gòu)；MAO/Ti涂層φcorr正移，Jcorr降低。外加軸向磁場，過濾帶電以及中性大顆粒粒子，有利于致密化鍍層，但提高弧斑運(yùn)動速度，升高陰極靶溫度，增加靶材的液滴數(shù)量，必須加以控制；Ti鍍層提高了MAO膜對鎂合金基體的腐蝕防護(hù)能力，但仍有待于通過工藝調(diào)整致密化鍍層，進(jìn)一步強(qiáng)化MAO/Ti涂層的綜合性能。
關(guān)鍵字: 鎂合金；涂層；微弧氧化；物理氣相沉積；鈦；耐蝕性
（1. School of Materials and Chemical Engineering, Sichuan University of Science and Engineering, Zigong 643000, China;
2. Material Corrosion and Protection Key Laboratory of Sichuan Province,
Sichuan University of Science and Engineering, Zigong 643000, China）
Abstract:The MAO/Ti composite coating was fabricated on AZ31B Mg alloy through a combined process of micro-arc oxidation (MAO) with multi-arc ion plating. The morphology, composition, phase structure and corrosion resistance of the coatings were evaluated using SEM, EDS, XRD and electrochemical methods. The results show that, with the magnetic current increasing from 0 A to 20 A, the temperature of vacuum chamber increases to 192 ℃ from 128 ℃, and the number of the droplet with large size on MAO/Ti coating decreases. When the deposition time increases from 30 min to 120 min at magnetic current of 10 A, the temperature of vacuum chamber increases sharply, the droplet number increases gradually, and the surface of MAO/Ti coating appears micro-cracks. However, under condition without magnetic field, the surface of the MAO/Ti coating presents plenty of droplets with the deposition time increases from 30 min to 120 min, and the surface of MAO coating is coated gradually by the Ti coating. The phase structures of MAO coating don’t change during this multi ion plating, while the φcorr of the MAO/Ti coating shifts to a positive potential, and the Jcorr decreases slightly. It can be concluded that the neutral or charged particles with large size may be filtered or decreased by controlling the magnetic current. Meanwhile, the magnetic increases movement velocity of the arc spot and rises the temperature of the cathode target, which could result in an increasing of droplets on the MAO/Ti coating. Although all results prove that the Ti coating further enhances the corrosion protection ability of the MAO coating on AZ31 Mg alloy, the compact Ti coating is required to be fabricated to provide a better properties through process optimization.
Key words: magnesium alloy; coating; plasma electrolytic oxidation; physical vapour deposition; titanium; corrosion resistance
