MEVVA離子源植入Cr對CrN硬質膜與AISI 4140上之抗腐蝕行為研究

Effect of MEVVA implanted Cr on the corrosion resistance of CrN coated on steel

金屬蒸氣真空電弧（MEVVA）電漿，是用於從事材料表面改質的一種嶄新技術。在工業上陰極電弧法常用來沉積CrN硬質膜，以增加鋼材抗腐蝕能力。本研究以MEVVA為離子源經植入各表面改質後腐蝕行為的影響，分別以AISI 4140低合金鋼基材表面植入Cr（Cr/steel），並以陰極電弧法沉積CrN膜（CrN/Cr/steel），及只沉積CrN膜（CrN/steel）的試片探討其在0.1N HCl之抗蝕能力。首先以XRD和SIMS方法了解植入鉻及CrN鍍膜的結構和組成，並藉由電化學交流阻抗頻譜法（EIS）量測極化阻抗Rp，經腐蝕測試後的試片以SEM觀察微結構。實驗結果顯示，以MEVVA離子源植入Cr不僅可降低沉積CrN鍍膜時之孔洞缺陷，此CrN層也大幅提高鋼材的腐蝕阻抗。

Metal vapor vacuum arc (MEVVA) source implantation is a very attractive application for surface modification. Cathodic arc plasma deposition of CrN coating is applied in an industrial scale to improve the corrosion resistance of AISI 4140 steel. The effect of the Cr implanted by MEVVA (Cr/steel) on the corrosion behavior of CrN/steel through the surface modification was investigated. Both AISI 4140 steel and its coated assemblies (Cr/steel, CrN/steel, and CrN/Cr/steel) were evaluated in aerated 0.1N HCl solution. The crystal structure and compositional distribution for the MEVVA implanted Cr and cathodic arc deposited CrN on steel were studied by XRD and SIMS. The polarization resistance (Rp) for all samples was measured and compared using electrochemical impedance spectroscopy (EIS). The corrosion morphology of the samples was examined by SEM. The results indicated that the corrosion resistance of steel was significantly enhanced by MEVVA Cr ion implantation through the reduction of not only by defect on the CrN coating but also by increase the corrosion resistance by the CrN coating.