鈦金屬電漿電解氧化鍍層之顯微結構、機械性質及生物相容性研究

Microstructure, Mechanical Property and Biocompatibility of Plasma Electrolytic Oxidation Coating on Titanium

鄭凱文(Kai-Wen Cheng) ； 曾傳銘(Chuan-Ming Tseng)

《真空科技》 33卷2期 (2020/06) Pp. 63-78

摘要

在本研究中，擬利用電漿電解氧化（PEO）技術在不同鋁酸鈉濃度的磷酸鈉電解液中，於鈦金屬表面製備具有多孔狀鈦酸鋁（Al_2TiO_5）及二氧化鈦（TiO_2）鍍層。藉由X-ray繞射儀（XRD），掃描式電子顯微鏡（SEM），（掃描）穿透式電子顯微鏡（STEM），能量光譜散射儀（EDS），刮痕附著度試驗及磨耗試驗等方法，研究不同濃度電解液對PEO鍍層的顯微結構及機械性質之影響。實驗結果發現：於鋁酸鹽和磷酸鹽組成的電解液中製備的PEO鍍層有最佳的附著性，其中在3g/L鋁酸鈉和10g/L磷酸鈉的電解液中，製備之PEO鍍層對鈦金屬的附著力最佳。由XRD和截面SEM-BDS的分析結果顯示，以鋁酸鹽和磷酸鹽作為電解液時鈦金屬上的PEO鍍層主要由鈦酸鋁Al_2TiO_5和金紅石-TiO_2組成。再者，於3g/L鋁酸鈉和10g/L磷酸鈉電解液中，改變PEO製程時間20s〜600s，藉此評估PEO鍍層的成長機制。由XRD結果發現鍍層形成初期主要為銳鈦礦二氧化鈦（＜20s），隨著電壓持續增高，鍍層結構會以銳鈦礦與金紅石兩種二氧化鈦結晶相共存（~40s），當電壓達到微弧放電階段以後且穩定維持在450V（＞ 90s），鍍層外層會出現鈦酸鋁尖晶石結構相。此外，由STEM-EDS分析結果顯示鋁酸鹽有助於PEO鍍層形成Al_2TiO_5相，首先形成Al_2TiO_5的非晶相，當電壓達到微弧放電階段Al_2TiO_5的非晶相會轉變成結晶相。本研究最後探討PEO鍍層對骨瘤細胞（MG63）的生物相容性及細胞貼附性質的影響，由體外細胞增殖及活性試驗結果顯示：相較於鈦金屬，PEO鍍層具有多孔狀的表面可以更好的提供細胞貼附及生長。

關鍵字

電漿電解氧化（PEO） ； 二氧化鈦 ； 鈦酸鋁 ； 附著性 ； 細胞增殖

並列摘要

In this study, we successfully prepared the porous Al_2TiO_5-TiO_2 PEO coating on titanium via plasma electrolytic oxidation (PEO) in aluminate-phosphate electrolyte. The microstructure and mechanical property of Al_2TiO_5-TiO_2 PEO coating were investigated by X-ray diffractometer (XRD), scanning electron microscope (SEM), (scanning) transmission electron microscope (STEM), energy-dispersive X-ray spectroscopy (EDS), α-step profilometer, scratch adhesion test and pin-on-disc wear test. The good adhesion of PEO coating on titanium is achieved by using the electrolyte with 3g/L sodium aluminate and 10g/L sodium phosphate. According to XRD and cross-sectional SEM-EDS, the PEO coatings on titanium are mainly composed of Al_2TiO_5 and rutile-TiO_2. Furthermore, the growth mechanism of the PEO coating was systematically studied on the coatings after PEO process in the electrolyte with 3g/L sodium aluminate and 10g/L sodium phosphate after processing durations from 20s to 600s, respectively. It can be found that anatasc-TiO_2 formed on pure Ti at the early stage (＜20s) and the structure of PEO coating was changed from ＂anatase-TiO_2 single phase＂ to ＂anatase and rutile-TiO_2 mix-phases＂ at the sparking stage (~40s). While the PEO voltage reached above 450 volts (＞ 90s), the aluminum titanate (Al_2TiO_5) was formed on the top layer of PEO coating. Finally, the proliferation and viability of human osteosarcoma (MG-63) cells cultured on Al_2TiO_5-TiO_2 PEO coatings were investigated and monitored by spectrophotometric measurement of mitochondrial dehydrogenase activity. The relative cell viability was calculatcd by comparing its optical density at 490 nm with that of the untreated control cells. As compared to pure titanium, the adhesion and proliferation of MG-63 cells were improved on porous Al_2TiO_5-TiO_2 PEO coating.

並列關鍵字

Plasma electrolytic oxidation(PEO) ； TiO_2 ； Al_2TiO_5 ； adhesion ； proliferation