5083鋁鎂合金表面無電鍍鎳磷奈米粒子複合塗層的腐蝕磨耗性質

無電鍍鎳沉積於基材上，有助於增加基材的耐腐蝕與耐磨耗性，因此廣泛應用在石油、化學、塑膠、機械、電子、軍事、航空等工業。本研究以無電鍍法，在無電鍍鎳液加入不同濃度1、10g/L的二氧化鈦及奈米碳管鍍析於5083鋁鎂合金基材表面上，以探討無電鍍鎳層與無電鍍鎳複合鍍層，分別對鍍膜的耐磨耗、耐腐蝕、耐腐蝕磨耗做研究比較。首先利用掃描式電子顯微鏡(SEM)和X光能量散射分析儀(EDS)，對鍍膜腐蝕前後的表面微結構與形貌及元素成分含量分析討論，以維克氏微硬度測試與表面粗度計量測鍍膜硬度及表面粗糙度。電化學動態極化方法，量測分析鍍膜的抗腐蝕與抗腐蝕磨耗性，與浸漬腐蝕實驗量測分析鍍膜的抗腐蝕性。以及使用無電鍍鎳氧化鋁鍍膜塊對燒結氧化鋁陶瓷環，鍍膜表面進行腐蝕磨耗試驗，於 3.5％NaCl腐蝕溶液環境下。實驗結果顯示無電鍍鎳奈米二氧化鈦及奈米碳管濃度1、10g/L複合鍍層時，奈米二氧化鈦及奈米碳管的鍍膜都有均勻及緻密附著，無電鍍鎳-磷(electroless Ni-P)奈米粒子的添加都可改善耐腐蝕磨耗性,其中奈米碳管又比奈米二氧化鈦來的好。在3.5％NaCl腐蝕溶液進行電化學腐蝕實驗時，無電鍍鎳-磷加上濃度10g/L奈米碳管(electroless Ni-P+CNT 10%)在3.5％的NaCl電化學腐蝕實驗中，相較下都有比較佳的抗腐蝕現象。浸漬腐蝕實驗中,也發現無電鍍鎳-磷加上濃度10g/L奈米碳管(electroless Ni-P+CNT 10g/L) 試片的腐蝕重量損失是最少的。

關鍵字

無電鍍鎳；奈米二氧化鈦；奈米碳管；電化學動態極化；腐蝕磨耗

並列摘要

Deposition of nickel coating on substrate, the coatings have been widely used in the oil, chemical, plastic, mechanical, an electronic, military affairs and aviation industries owing to increase the wear, abrasion and corrosion resistance of substrate. The purpose of this study is to investigate the wear, corrosion and corrosion-wear resistance of electroless nickel coatings and electroless nickel composite coatings containing Ni-P/ nano-CNT/nano-TiO2 1g/L 10g/L additive with different concentration for compared. Surface morphologies, element compositions and surface roughness of the composite coatings before and after all tests are analyzed by scanning electron microscopy (SEM), X-ray energy dispersive analyzer (EDS) and surface roughness measurement. Also, the surface hardness of these composite coatings is measured by Micro Vickers Hardness test instrument. Electrochemical polarization measurements are performed for analyzing both corrosion and wear-corrosion characteristics under static and wearing conditions, using the block-on-ring surface friction manner to evaluate the dry wear and wear-corrosion behavior of these composite coatings in air and 3.5% NaCl solution, respectively. The friction ring counterpart is made of a sintered Al2O3. The purpose of this study is to evaluate the corrosion and wear-corrosion resistance properties of electroless Ni/nano-TiO2 and Ni/CNT plated nano-composite coatings on AA5083 alloy in 3.5 wt.% NaCl solution. The nano-composite coatings were prepared by electroless plating method that the nano-TiO2 (15 nm) and Carbon nano-tube (CNT, 5nm) particles were added into the eletroless Ni plating solution with a low and a high concentration of 1 g/L and 10 g/L for comparison, respectively. The corrosion resistance properties of the nano-composite coatings were examined by both potentiodynamic polarization and immersion corrosion test. The experimental results indicated that both Ni/nano-TiO2 and Ni/CNT nano-composite coatings exhibited an uniform and a compact surface morphology, not only improving the corrosion and wear-corrosion resistance of the AA5083 Al-Mg alloy but also superior to the electroless Ni-P coating. Both the corrosion and wear-corrosion resistance of the nano-composite coatings were enhanced significantly at high concentration of 10 g/L, in addition that the CNT added was superior to the nano-TiO2 added electroloss plating solution.