- 學位論文
鎂合金經陽極處理後在含有石墨烯的人工體液中的生醫相容性與腐蝕磨耗研究
Biocompatibility and Corrosive Wear of Anodized Magnesium Alloy in a Simulated Body Solution Containing Graphene
摘要
本論文研究以浸泡技術在鎂合金AZ30、AZ60與AZ91D表面，經過陽極處理後，浸泡在人工體液中以形成磷酸鈣/石墨烯複合塗層，分析複合塗層結構和硬度值以及在Hanks′ solution中(pH 7.4)，其耐腐蝕性和耐磨耗性。 實驗中使用鎂合金AZ30、AZ60、AZ91D經過陽極處理後，進行浸泡形成磷酸鈣/石墨烯(1g/L)，以維克氏硬度量測儀測得複合塗層之硬度，再置入Hanks′ solution (pH 7.4)中，再以燒結氧化鋁(Al2O3)陶瓷環使用塊對環(Block-on-ring)表面磨耗方式，分析耐磨耗性，以及使用電化學極化實驗，分析耐腐蝕性，最後用掃描式電子顯微鏡(SEM)和能量散射光譜儀(EDS)，分析複合塗層在腐蝕和磨耗前後的表面形態和元素成分。 實驗結果顯示鎂合金AZ30、AZ60、AZ91D，添加石墨烯所形成浸泡磷酸鈣/石墨烯(1g/L)複合塗層，會有較高的硬度值、耐腐蝕性與耐磨耗性，而鎂合金基材經過陽極處理後，會提升浸泡磷酸鈣/石墨烯(1g/L)複合塗層的附著性、緻密性與沉積效率，而複合塗層的鈣-磷比也會提高。因此對於表面硬度、耐腐蝕性、耐磨耗性與生醫相容性，有更好的提升效果，而發現所有鎂合金中以在經陽極處理後的AZ60所形成的複合鍍層會有最好的表面硬度、耐腐蝕性、耐磨耗性與生醫相容性。
並列摘要
The purpose of the present study is to evaluate the structure and mechanical properties of the calcium phosphate/nano-graphene composite coatings formed by immersing in a simulated body solution as well as their effect on the corrosion and wear-corrosion resistance of AZ30, AZ60 and AZ91D magnesium alloys of in Hanks′ solution. The anodizing process was performed on magnesium alloys surface to enhance the adhesive of these composite coatings on magnesium alloys. The surface morphologies and element compositions of the composite coatings before and after all tests are analyzed by scanning electron microscopy (SEM) and X-ray energy dispersive analyzer (EDS). The surface hardness of the specimens was measured by a Vickers′ hardness tester. Electrochemical polarization measurements are performed for analyzing corrosion characteristics, and using the block-on-ring surface friction manner to evaluate the wear-corrosion behavior of these composite coatings in Hanks′ solution. Experimental results indicated that the hardness of all magnesium alloys was increased due to the anodizing treatment, and that could enhanced the calcium phosphate coating in addition to the calcium phosphate/nano-graphene composite coatings. The coatings exhibited more uniform, dense and adhesive than that of no anodizing treatment. When the nano-graphene particles were added into the solution, it is found that the nano-graphene particles could be co-deposited on the magnesium alloys and reinforced the calcium phosphate coating, increasing the hardness and refining the structure, also increasing the ratio of Ca to P. Moreover, the corrosion, wear resistance and biocompatibility of the calcium phosphate/nano-graphene composite coatings formed by immersing were improved significantly for AZ60 magnesium alloy.