纯钛阳极氧化及表面薄层羟基磷灰石形成技术的研究 Ⅲ.蒸汽温度及Ca^(2+)浓度对氧化膜表面析出晶体性能的影响

Study on anodic oxidation of CP titanium with thin hydroxyapatite layers Ⅲ Effects of steam temperature and calcium ion concentration on the precipitation of crystals on the anodic oxide films

目的 :了解蒸汽温度及Ca2 +浓度对氧化膜表面析出晶体性能的影响。方法 :将钛片分别在六种不同Ca2 +浓度的电解质溶液中进行电解 ( β-磷酸甘油钠 :醋酸钙=0.04M:0.15M ,0.04M:0.20M ,0.04M:0.25M ,0.04M:0.30M ,0.04M:0.35M ,0.04M:0.40M)和在三种不同蒸汽温度下进行水热处理 (200℃ ,250℃ ,300℃ )。结果 :随着水热温度的增高 ,钛片表面晶体开始析出并增多 ,在200℃水热处理时 ,钛片表面几乎无晶体析出 ,300℃为较理想的水热处理温度 ;随着Ca2 +浓度的增加 ,钛片表面晶粒逐渐变细、增多 ,形状逐渐规则 ,Ca/P比则从1～3不等。结论 :蒸汽温度以及Ca2 +浓度对于氧化膜表面结晶物和HA的析出有重要的影响。HA在高温下生成 ,因而较稳定。此外 ,在贫钙状态 ,析出晶体较为粗大 ,而在富钙状态 。

Objective:To know the effects of steam temperature and calcium ion concentration on the hydrothermal treated anodic titanium oxide films. Methods:commercially pure titanium plates were anodized in electrolytic solution with six different calcium ion concentrations(a constant of 0.04M β-glycerophosphate sodium and calium acetate concentrations varied from 0.15M to 0.40M),and hydrothermal treated at three different steam temperatures (200V,250V,and 300V). Results:SEM results found that precipitated crystals tended to be finer with increasing calcium ion concentration.When calcium acetate concentration was 0.15M or 0.20M,the anodic oxide films were dotted with relatively large and columnar crystals. But when calcium acetate concentration was varied from 0.25M to 0.40M,fine and numerous crystals were precipitated, completely covered the titanium plates'surface.And with EDAX analysis,Ca/P ratio from 1 to 3.In addition, SEM results indicated that there had nearly no crystals precipitated on the titanium plates below 200℃,compared with moderate crystals precipitated on the plates at 300℃. Conclusion:the morphology and composition of precipitated crystals were determined by regulating the calcium acetate concentration at a constant β-glycerophosphate sodium concentration.Near-stoichiometric HA crystals seemed to be precipitated when calcium acetate concentration was 0.25M and β-glycerophosphate sodium concentration was 0.04M.Steam temperature was another important factor to influence crystal growth on the titanium surface. It was considered that hydroxyapatite was formed by the reaction of Ca and P contained in the anodic oxide films with hydroxyl group in high-pressure steam. 300℃ was a better temperature for crystal growth. Moreover,HA was formed at high temperature,which meant HA was stable for its high reactive energy.