應用常壓電漿技術沉積氧化矽薄膜於AZ31鎂合金提升其抗腐性之研究

Deposition of Silicon Oxide Films by Atmospheric Pressure Plasma for the Corrosion Protection of AZ31 Magnesium Alloys

本研究藉由常壓電漿輔助化學氣相沉積法，以四乙氧基矽烷（Tetraethoxysilane, TEOS）作為前驅物，沉積氧化矽薄膜於AZ31鎂合金基材，得到奈米顆粒氧化矽薄膜。利用場發掃描式電子顯微鏡、原子力顯微鏡、X射線光電子能譜，分析在不同之氧氣載氣流量下薄膜表面形貌、微觀結構與粗糙度之改變，最後以電化學分析抗腐蝕能力。根據研究結果說明，可以得到低碳之氧化矽薄膜，且經由電化學分析腐蝕行為可證實，以常壓電漿製備氧化矽薄膜沉積於鎂合金上，其腐蝕電位從-1.46V提升至-1.42 V，而腐蝕電流密度從2.4×10-3A cm-2低至7.82×10-5 A cm-2，有助於提升鎂合金之抗腐蝕能力。

This study is to evaluate the feasibility and application of silicon oxide (SiOx) thin films as anti-corrosion layers for AZ31 magnesium alloys by atmospheric pressure plasma. The surface morphologies of deposited SiOx film were examined by contact angle goniometer, atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM). The chemical compositions were analyzed by Fourier transform infrared spectroscopy (FTIR) and electron spectroscopy for chemical analysis (ESCA). The corrosion resistance of Mg alloy and SiOx film was evaluated using potentiodynamic polarization measurements. The results show that the anticorrosion behavior of stoichiometric SiO2 film on AZ31 deposited at the O2 flow rate of 600 sccm possessed a higher corrosion potential (Ecorr = -1.42 V) and a lower corrosion current (Icorr = 7.82×10-5 A cm-2) as compared to the raw AZ31 materials (Ecorr = -1.46 V; Icorr = 2.40×10-4 A cm-2).