鎂鋰合金雙極脈衝微弧氧化之表面平整化與抗腐蝕性研究

A study on the Surface Flattening and Corrosion Resistance in Bipolar pulsed Micro-arc Oxidation of a Mg-Li Alloy

徐宇傑(Yu-Chieh Hsu)

指導教授 ： 楊智富 ； 楊木榮

大同大學/工程學院/材料工程學系所/碩士(2012年)

摘要

本研究藉由掃描式電子顯微鏡/能量散佈光譜儀(SEM/EDS)、X光繞射儀(XRD)、感應式耦合電漿原子發射光譜分析儀(ICP-OES)、膜厚計、粗度儀、及恆電位儀等設備，探討LAZ951(Mg-9 Li-5 Al-1 Zn)鎂鋰合金經雙極(Bipolar)微弧氧化(MAO)處理之氧化膜平整度化與抗蝕性，其微弧氧化製程參數包含反應時間、逆向負載 Ton－ 時間及逆向負載電流。結果顯示，當製程之反應時間、逆向負載電流(－I)及逆向負載時間( Ton－)三項參數分別為 10 min、1 A/dm2 及 3,000 μs 時，可獲致最佳組合之抗蝕性與表面平整度。再將 MAO 試片分別以水溶漆及水玻璃進行後處理，結果顯示，試片經水溶漆處理後，可獲得良好之表面平整度，且藉由添加 silane 來增加水溶漆之吸附性，其中以添加 2 % silane之水溶漆附著性最佳，且具最佳之抗蝕性，其 Icorr 值為 3.6×10－9 Amp/cm2 ，比未施作水溶漆後處理者(Icorr = 1.2×10－7 amp/cm2)優異許多。

關鍵字

微弧氧化 ； 抗腐蝕性 ； 表面平整度 ； 鎂鋰合金

並列摘要

In this research the corrosion resistance and the surface flattening of a bipolar pulsed Micro-arc Oxidation (MAO) treatmented LAZ951 Mg alloy (Mg-9Li-5Al-1Zn) were studied. The main process variables include processing time from 5 to 20 min, reverse loading current (-I) from 1 to 3 Amp/dm2 and reverse loading time (Ton-) from 1,000 to 3,500 μs. Poperties of the resulted MAO film were examined by using SEM, EDS, XRD, ICP-OES, coating thickness gauge, surface topology interferometer and potentionstate. The results show that, when operated under a specific condition of processing time of 10 min, reverse loading current of 1 Amp/dm2 and reverse loading time of 3,000 μs, a MAO film with most satisfactory combination of corrosion resistance (Ecorr = -1.3 V, Icorr = 1.8×10－8 amp/cm2) and surface flatness (Rz = 7.6 μm) was produced. In the post-MAO treatment, it was found that a water soluble coating with 2% silane can effectively enhance both the corrosion resistance (Ecorr = -1.42 , Icorr = 3.5×10－9 amp/cm2) and surface flatness (Rz = 3.4 μm) of the MAO specimen.

並列關鍵字

Mg-Li alloy ； corrosion resistance ； surface flatness ； micro-arc oxidation

參考文獻

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