陰極電化學合成氧化鋯陶瓷膜於牙科鈷鉻合金在人工唾液中之耐蝕性研究

Corrosion Resistance of Cathodic Electrosynthesis ZrO2 Coatings on Dental Co-Cr Alloys in Artificial Saliva

本研究以添加1g/L聚二甲基二烯丙基氯化氨（polydimethyldiallylammonium chloride, PDDA）之0.05M硝酸氧鋯（ZrO(NO3)2）水溶液作為電解液，透過陰極電化學法於牙科用鈷鉻合金表面沉積氫氧化鋯膠體再經500℃燒結1小時得到氧化鋯陶瓷膜。透過於人工唾液中之動態極化試驗及模擬刷牙之磨耗腐蝕試驗，了解氧化鋯陶瓷膜對於鈷鉻合金之抗蝕性。實驗顯示，經被覆氧化鋯陶瓷膜之試片明顯有較高之腐蝕電位、較低之腐蝕電流密度，動態極化試驗後之人工唾液經感應偶合電漿－原子發射光譜儀（ICP-AES）分析，結果顯示氧化鋯鍍膜可以較低的鈷離子釋放量達57.2%，鉻離子釋出量達70.6%；模擬刷牙之磨耗腐蝕試驗發現鈷鉻合金試片會降低腐蝕電位及提高腐蝕電流密度，而被覆氧化鋯陶瓷膜之試片則無明顯變化，顯示氧化鋯陶瓷膜能提高鈷鉻合金於人工唾液中之耐蝕性。

In this study, 0.05M zirconium nitrate (ZrO(NO3)2) aqueous solution was added with 1ml / L polydimethyldiallylammonium chloride (PDDA) as the electrolyte, through the cathodic electrosynthesis method to produce zirconium hydroxide gel-coating on dental Co-Cr alloy, and the gel-coated specimens were annealed at 500℃ for 1 hours in air to obtain a zirconia coating. The dynamic polarization and wear-corrosion test in artificial saliva results showed the higher corrosion potential and lower corrosion density of electrolytic ZrO2 coating than the uncoated one. The amounts of released cobalt and chromium ions were evaluated using ICP-AES from the solution after dynamic polarization test. The ZrO2 coating reduced the cobalt and chromium ions release level by 57.2% and 70.6%, respectively. The ZrO2 coating revealed a better quality in corrosion resistance than the uncoated one.