- 學位論文
微弧氧化電壓對氫氧基磷灰石披覆於鈦板之影響
The effect of the Voltage Level on Hydroxyapatite Coating of Titanium Plate by Micro-arc Oxidation
摘要
本研究採用微弧氧化法沉積氫氧基磷酸鈣於鈦片上。以濃度0.075M Ca(CH3COO)2•H2O,0.025M Ca(H2PO4)2•H2O,0.04M EDTA-2Na 和0.375M NaOH等體積混合為電解液,並加入摻雜10g/L的氫氧基磷酸鈣粉末的10%酒精溶液,利用微弧氧化法探討在定電壓模式下,不同電壓下對氫氧基磷灰石批覆於鈦上之影響。當陽極電壓介於275V-325V之間,微弧氧化膜隨著電壓的增加,結晶性逐漸增加,其中主要的成分為銳鈦礦及氫氧基磷灰石；當陽極電壓增加到350V時,由於所提供的能量超越膜層所能負荷,披覆於上層之氫氧基磷酸鈣膜層產生剝落及崩離的現象,使得氫氧基磷酸鈣結晶度瞬間蛻減,再加上高溫高電壓的能量衝擊下,金紅石相產生與銳鈦礦並存於高電壓(350V)下。此外,微弧氧化膜隨著電壓的增加(275-350V),膜層的厚度也隨之增加且變得越來越緻密；在電壓增加的同時,電流也隨之增加且劇烈,導致膜層表面的粗糙度也隨之增加；經由水接觸角的量測下得知微弧氧化膜在350V的高電壓下有很好的親水性質,接觸角度隨著電壓的增加而減少,此與微弧氧化膜表面為孔洞結構有很大的關係；膜與基板的附著性於洛氏C壓痕測試下於電壓350V得到最差的附著性,推論可能與沉積速率增加導致生成膜層的品質降低有關。
並列摘要
Hydroxyapatite crystallite has successfully been deposited on titanium plates by micro-arc oxidation in this work. The electrolytic solution is composed of mixture of electrolytic solution and 10g/L hydroxyapaite powders with 10% alcohol solution in this experiment. The electrolytic solution contains 0.075M Ca(CH3COO)2•H2O,0.025M Ca(H2PO4)2•H2O,0.04M EDTA-2Na and 0.375M NaOH. Different voltage is employed on titanium plates which immersed in electrolytic bath to observe the characteristic of surface on hydroxyapatite coating. As voltage at the interval of 275 to 325V, the crystallinity of hydroxyapatite crystal increased with increasing voltage and the primary phases are hydroxyapatite and anatase , as shown in XRD patterns. However, the high power input will also incur ablation and crack. On the other hand, the thickness of coating also increased with increasing voltage and became more uniform .Hence, increase voltage lead to the increase in the roughness on surface of coating. The porous structure on surface exhibits better hydrophilic property and smaller water contact angle. The number of micropores increase as voltage increase, indicative of smaller water contact angle. The microarc oxide coating seemingly bears no significant relation with voltage, but affected by other factors, such as deposition rate. The increase of deposition rate might be increase the growth rate of coating but decreased the quality of coating.