純鈦上之含鈣磷氧化層及其水熱處理

Phosphorus/Calcium-Containing Oxide Layer on Titanium and Its Hydrothermal Treatment

阮富華(Fu-Wa Un)

指導教授 ： 潘永寧

國立臺灣大學/工學院/機械工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.01475

摘要

本研究針對人骨植入材進行表面處理以改善植入材本身之生物相容性，以生醫常用之純鈦板(commercial pure titanium, c. p. Ti)進行微弧氧化處理(microarc oxidation, MAO)，於表面形成一層含Ca、P之緻密anatase TiO2，再經由後續之水熱處理(hydrothermal treatment, HT)生成氫氧基磷酸鈣(Ca10(PO4)6(OH)2, HA)，最後於表面形成一HA/TiO2之披覆層。在微弧氧化處理部份，以不同之電壓值為參數，而在水熱處理部份，以不同之溶液pH值、處理溫度、持續時間為參數。試片經微弧氧化處理之後，分別以SEM及EPMA來觀察試片表面之氧化層形態及Ca、P在表面之分佈情形，並以拉伸試驗測試表面氧化層之界面強度。試片經水熱處理後，以SEM觀察表面HA之生長形貌，再以XRD分析表面之化學組成，最後綜合分析結果來決定較佳之處理條件。
研究結果指出，氧化層較表面之Ca、P併入較底層為高，隨著微弧氧化電壓之增高，表面之氧化層越厚，孔洞直徑越大，且披覆層與底材之界面強度亦隨之下降，特別當電壓為250V以上時，對於不同組次進行測試所獲得之界面強度均大不相同，起伏甚大，歸因於孔洞大小較大、氧化層較厚以及微裂縫之出現。而配合後續水熱處理，必須同時滿足微弧氧化電壓要達200V或以上，及後續水熱熱處理持續溫度達250℃，才較有生長出HA之能力，250V或以下因Ca、P併入較少，持續時間增加有利於其擴散而有利HA生長，其中300V以上因Ca、P併入較多，2小時便能生長出大量且細小之HA，時間延長引發HA之熱分解成磷酸三鈣且HA之再生成而變得粗大。

關鍵字

純鈦板 ； 微弧氧化 ； 水熱法 ； anatase TiO2 ； HA ； 生物相容性

並列摘要

This study employed micro-arc oxidation (MAO) and hydrothermal treatment (HT) to modify the surface characteristics of commercial pure Titanium (c.p.Ti) for improving the biocompatibility of the test material for human implants application. The parameters investigated include voltage for MAO and pH value, treatment temperature and duration for HT. The surface characteristics were analyzed by SEM, EPMA and XRD, and the bonding strength of the coating was also tested.
The results indicate that a dense Ca, P-containing anatase TiO2 layer was formed by micro-arc oxidation, and HA (Ca10(PO4)6(OH)2) was crystallized on the oxide layer by the subsequent hydrothermal treatment. As a result, HA/TiO2 was formed on the surfaces of the treated material. It has been observed that both the thickness of the oxide layer and the size of pores increase with increasing MAO voltage. In addition, the Ca and P contents in the oxide layer increase from the substrate/oxide interface toward the outmost surface. On the other hand, the bonding strength decreases with increasing MAO voltage. The rather wide variation in bonding strength for voltages exceeding 250V is due to relatively thick oxide layer, large pores and the presence of micro-cracks. Regarding the effect of hydrothermal treatment, HA will form only when the MAO voltage is above 200V and the HT temperature is above 250oC. For MAO voltage below 250V (but above 200V), increasing treatment time promote the diffusion of Ca and P and hence the formation of HA, due to relatively low Ca and P contents in the oxide layer. On the other hand, for MAO voltage of 300V, the results show that the treatment time of 2 hours is sufficient to form HA, due to relatively high Ca and P contents in the oxide layer. However, HA will transform to tricalcium phosphate by means of thermal decomposition if the treatment time is too long. Based upon the results obtained herein, the optimal treatment conditions are: 230V-deionized water/pH9-250oC-6hours.

並列關鍵字

Pure Ti ； Micro-arc oxidation ； Hydrothermal treatment ； HA ； biocompatibility

參考文獻

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