電鍍磷酸鈣/奈米二氧化鈦複合塗層在鈦合金表面的磨耗腐蝕特性研究

本論文主要是研究以電鍍技術在Ti-6Al-4V表面經陽極處理後，沉積電鍍磷酸鈣-奈米二氧化鈦複合鍍層，分析基材鍍膜結構與機械性質、耐腐蝕以及耐磨耗腐蝕之改善效應。實驗中使用Ti-6Al-4V合金原基材經陽極處理，陽極處理操作條件在常溫下、電壓為10V、陽極處理的時間為(40m、50m、60m、120m、180m)，再於電鍍磷酸鈣液中添加奈米二氧化鈦(濃度為10g/L)，進行電鍍磷酸鈣-奈米二氧化鈦60分鐘。再以塊對環(Block-on-ring)表面磨耗方式在模擬人工體液(Hanks’ solution，pH7.4)溶液下分析複合鍍膜的耐磨耗腐蝕性，磨擦環為燒結氧化鋁(Al2O3)陶瓷。使用掃描式電子掃描鏡(SEM)和X光能量散射光譜儀(EDS)，來分析複合鍍膜在腐蝕磨耗前後的表面微結構與元素成分、利用原子力顯微鏡(AFM)測量鍍層表面粗糙度、微克式硬度量測儀測得鍍膜之硬度。實驗結果顯示Ti-6Al-4V合金表面經陽極處理後硬度增加，而發現在電鍍磷酸鈣液中能有小的增加鍍層表面晶粒均勻附著及硬度值。而在電鍍磷酸鈣液中加入奈米二氧化鈦時，更能增加耐腐蝕性與耐磨耗腐蝕性，適當的陽極處理將能有效提升電鍍磷酸鈣-奈米二氧化鈦複合鍍層的沉積效率、緻密性與附著性，因而對於表面硬度、耐腐蝕性與耐磨耗腐蝕等均有顯著的改進效果。

關鍵字

陽極處理；電鍍磷酸鈣複合鍍層；磨耗腐蝕；奈米二氧化鈦；塊對環；磨耗與腐蝕

並列摘要

The purpose of the present study is to evaluate the structure and mechanical properties of the electroplated calcium phosphate/nano-TiO2 composite coatings as well as their effect on the corrosion and wear-corrosion resistance of Ti-6Al-4V alloy in a simulated body solution (Hanks’ solution). The anodizing process was performed on Ti-6Al-4V alloy surface to enhance the adhesive of these composite coatings on Ti alloy. The anodizing treatment was conducted at 10V and room temperature with different anodizing time of 40min, 50min, 1h, 2h and 3h. The calcium phosphate was electroplated for 60 min, also nano-TiO2 (10g/l) particles were added to the plating solution for comparison. The 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 atomic force microscope (AFM). The surface hardness of the specimens was measured by a Vickers’ Hardness tester. Electrochemical polarization measurements are performed for analyzing corrosion characteristics, using the block-on-ring surface friction manner to evaluate the wear-corrosion behavior of these composite coatings in Hanks’ solution. The friction ring counterpart is made of a sintered Al2O3. Experimental results indicated that the hardness of Ti-6Al-4V alloy was increased due to the anodizing treatment, and that could enhanced the electroplated calcium phosphate coating in addition to the electroplated calcium phosphate/nano-TiO2 composite coatings. The coatings exhibited more uniform, dense and adhesive than that of no anodizing treatment. When the nano-TiO2 particles were added into the plating solution, it is found that the nano-TiO2 particles could be co-deposited on the Ti-6Al-4V alloy and reinforced the calcium phosphate coating, increasing the hardness and refining the structure. Moreover, the corrosion and wear–corrosion resistance of the electroplated calcium phosphate/nano-TiO2 composite coatings were improved significantly as a result of the nano-TiO2 particles added.