激光快速成型纯钛耐腐蚀能力研究

Effect of pH value on corrosion resistance of pure titanium by laser rapid forming

目的:评价不同PH值对激光快速成型纯钛的耐腐蚀性能的影响。方法:以锻造商业纯钛(CP-Ti),Ti-6Al-4V,Ti-6ALl-7Nb合金作为对照,将激光快速成型纯钛(LRF-Ti)试样分别浸入人工唾液(pH=7)和1%乳酸溶液(pH=2.3)中,在37℃恒温下浸泡7d±1h;分别采用肉眼和扫描电镜观察试样的表面形貌,采用电感耦合等离子体质谱仪(ICP-MS)来测定浸泡液中离子析出浓度。结果:肉眼观察未见各组试样表面颜色发生明显改变;扫描电镜观察可见浸泡于1%乳酸中的CP-Ti试样表面有明显腐蚀坑形成,但未见明显的腐蚀产物,其余各组试样表面均未发现明显腐蚀坑和腐蚀产物;在2种PH值的浸泡溶液中,LRF-Ti的Ti离子析出浓度均明显低于CP-Ti;在四种试样中,每种金属试样的钛离子析出浓度在不同溶液中由高到低为:乳酸>人工唾液。结论:低pH值会加速Ti离子的释放,且LRF-Ti在低pH值条件下的耐腐蚀性能优于CP-Ti,更适合用作人体植入材料。

Objective： To evaluate the effect of different pH values on corrosion resistance of Ti by laser rapid Forming. Methods： Specimens of laser rapid prototyping pure titanium （LRF-Ti） were immersed in artificial saliva （pH = 7） by forg- ing commercial pure titanium （CP-Ti）, Ti-6A1-4V and Ti-6ALI- And 1% lactic acid solution （pH=2.3） at 37 ~C for 7d ＋ lh respectively. Surface morphology of the specimens was observed with naked eyes and scanning electron microscopy, re- spectively, and determined by inductively coupled plasma mass spectrometry （ICP-MS） Immersion solution ion concentra- tion. Results： There was no obvious change of color on the surface of each sample. The scanning electron microscope showed that the surface of CP-Ti sample immersed in 1% lactic acid formed obvious corrosion pits, but no obvious corro- sion products were observed. In the other groups, no obvious corrosion pits and corrosion products were found on the sur- face of the sample. The Ti ion concentration of LRF-Ti was significantly lower than that of CP-Ti in two kinds of immersion solutions at pH value. For the four samples, Titanium ion concentration of metal samples in different solutions from high to low： lactic acid〉artificial saliva. Conclusions： Low pH accelerates the release of Ti, and LRF-Ti shows better corrosion re- sistance at lower pH than forged titanium, possibly making it more applicable as a human implant material.