【作者】 杨涵崧；

【导师】 李慕勤；

【作者基本信息】 佳木斯大学 ， 材料加工工程， 2007， 硕士

【摘要】 钛具有良好的生物相容性、力学性能和耐腐蚀性,为临床应用的主要金属材料。多孔钛由于具有一定的承载能力,其多孔结构有利于生物组织长入,成为近年来研究的热点。但如何获得孔隙可控,表面活性优异的多孔钛,还有待于深入研究。本文以碳酸氢铵做造孔剂,采用粉末冶金法制备出多孔钛,经碱处理及热处理表面改性,通过体外模拟研究其生物活性。使用电子分析天平、扫描电子显微镜、电液伺服万能材料试验机、能谱分析、X射线衍射等手段研究结构及性能。系统研究了碳酸氢铵加入量、烧结温度对多孔钛孔隙率、抗压强度的影响;孔隙率与碳酸氢铵加入量关系。提出将坯体烧结过程中的收缩看作碳酸氢铵留下孔的收缩和钛粉的收缩的观点,得出孔隙率的倒数和钛与碳酸氢铵质量比成一次函数关系的结论。提高烧结温度,碳酸氢铵留下孔的收缩和钛梁的收缩均增大。通过研究,多孔钛的抗压强度与多孔钛的相对密度成幂函数关系,提高烧结温度,幂次减小。研究表明,添加33.33wt%～63.64wt%的碳酸氢铵,1100℃、1150℃、1200℃真空烧结,制得孔隙率48.54%～81.23%、抗压强度5.11～89.86MPa不等的多孔钛。其中,1200℃烧结的钛孔壁相对密度超过95%,多孔钛孔隙率48.54%～77.24%、抗压强度19.85～89.86MPa、大部分孔径处于50～200μm。多孔钛具有孔隙贯通、孔分布均匀、孔隙率和强度可控、重现性好的特点。采用60℃、5mol/LNaOH溶液对多孔钛进行表面改性24小时,在基体表面生成厚度2μm左右的无定形钛酸钠和金红石凝胶层。针对改性后的多孔钛采取600℃热处理,钛酸钠从无定形态转为晶态,二氧化钛仍为无定形金红石型。体外模拟试验表明,经碱处理及热处理的多孔钛二周后表面生成了大量的生物活性羟基磷灰石和磷酸八钙,说明改性后的多孔钛具有较好的生物相容性和生物亲和性。更多还原

【Abstract】 Titanium is a main metal material applied to the clinic due to its good biocompatibility, mechanical property and corrosion resistance. In recent years, researches on porous titanium have gained much attention, because porous titanium has certain bearing capacity whose porous structure benefits for biological tissue to grow into. But how to obtain the porous titanium with controlled porosity and excellent surface activity requires further studies.Porous titanium was prepared by powder metallurgy and ammonium hydrogen carbonate was selected as pore former in this paper. The surface of porous titanium was modified by alkaline solution and heat treatment. Bioactivity was studied by simulation test in vitro. The structures and the properties of samples were characterized by means of electron analytical balance, scanning electron microscope (SEM), omnipotence material experiment machine, energy disperse spectroscopy(EDS) and X-ray diffraction (XRD).The effects of ammonium hydrogen carbonate content as well as sintering temperture on porosity and compressive strength of porous titanium were investged. Moreover, the relationship between the porosity of porous body and the content of ammonium hydrogen carbonate was studied systematically. The results showed that the shrinkage of titanium body was treated as the shrinkage of the pore left by ammonium hydrogen carbonate and titanium powder during sintering process. The reciprocal of porosity was expressed as a function of the quality ratio of titanium to ammonium hydrogen carbonate. The shrinkage of the pore left by ammonium hydrogen carbonate and titanium powder increased with sintering temperature heightened. The compressive strength was a power function of the relative density of porous titanium and the power reduced when sintering temperature was enhanced.The results have showed that when the content of ammonium hydrogen carbonate additive was 33.33wt%~63.64wt%, the porous titanium with porosity of 48.54%~77.24% and compressive strength of 19.85~89.86MPa was prepared at 1100℃, 1150℃and 1200℃vacuum sintering. Among them, the porous titanium sintered at 1200℃has relative density of 95% excess, porosity of 48.54%~77.24%, compressive strength of 19.85~89.86Pa and pore size of 50~200μm. The porous titanium prepared had the characteristics of interconnected pore, uniform pore size distribution, controlled porosity and intensity, good repetition.After the surface of porous titanium was modified 24h by 5mol/Lthermal alkaline solution at 60℃, the gel coating of amorphous Rutile and Na2TiO3 with 2μm thickness were formed on the surface of titanium matrix. After the modified porous titanium was treated at 600℃, the amorphous Na2TiO3 translated into crystal Na2TiO3 while amorphous Rutile had no change. The simulation test in vitro showed that plentiful bioactive hydroxyapatite and octacalcium phosphate formed on the surface of the porous titanium modified by thermal alkaline solution and heat treatment after two weeks, which indicated that porous titanium being modified had good biocompatibility and bioaffinity.更多还原