利用预钙化处理提高碱热处理多孔钛的表面生物活性  

Enhancement of The Bioactivity of Alkali-Heat Treated Porous Titanium by Pre-Calcification

作　　者：梁芳慧[1] 王克光[2] 周廉[2] 

机构地区：[1]东北大学,辽宁沈阳110004 [2]西北有色金属研究院,陕西西安710016

出　　处：《稀有金属材料与工程》2004年第10期1013-1017,共5页Rare Metal Materials and Engineering

摘　　要：采用粉末冶金方法制备多孔钛样品,孔隙率约为40%,最大孔径为240μm。经过NaOH溶液、热处理后,多孔钛再在Na2HPO4溶液和饱和Ca(OH)2溶液中分别浸泡进行预钙化处理。未经预钙化处理的样品在SBF中浸泡,形成表面磷灰石涂层约需28d的时间。经过预钙化的样品在SBF中浸泡只需4d,这说明预钙化过程大大提高了多孔钛的生物活性。其作用机理为:预钙化过程中样品表面的钛酸钠水解,形成带负电的Ti-OH基团,使Ca2+离子吸附到表面。在SBF中浸泡时,表面附近在短时间内达到钙-磷过饱和。且Ca2+离子增大表面附近的pH值,Ca2+离子和PO4离子、OH-离子的活度积增大,刺激了磷灰石成核并形成涂层。除碱热处理并预钙化的样品外,其余3-样品表面磷灰石的Ca/P原子比均小于人体自然骨的Ca/P原子比。涂层的结晶细小而薄,不破坏多孔钛的孔隙结构。The porous titanium with maximal pore size about 239 gin and 40% porosity was prepared by powder metallurgy process. The samples were subjected to NaOH solution and heat treatment, then immersed in Na2HPO4 solution and saturated Ca(OH)(2) solution to perform pre-calcification. The samples without pre-calcification were soaked in SBF (Simulated Body Fluid) for 28 d to form apatite coatings on surfaces. And the samples subjected to pre-calcification were soaked in SBF only for 4 d for apatite deposition, showing that pre-calcification enhanced the bioactivity of porous titanium remarkably. The mechanism of pre-calcification was explained as follows: during the pre-calcification process, the sodium titanate formed on surfaces of porous titanium by alkali-heat treatments would be hydrolyzed to produce negatively charged Ti-OH group, which absorb Ca2+ to surfaces. When samples were soaked in SBF, the Ca-P was supersaturated in shot time and the ion activity near the surfaces increased, which stimulated the nucleation and growth of the apatite crystal. Expect the samples subjected to alkali-heat and pre-calcification treatments, the Ca/P atom ratios of apatite coatings on the porous titanium for other samples were less than that of human bone. The thin coatings with fine crystal did not destroy the pore structure of porous titanium.

关 键 词：钛 多孔钛 碱热处理 磷灰石 涂层 预钙化 

分 类 号：TG156[金属学及工艺—热处理]