【作者】 惠燕先；

【导师】 李光玉；

【作者基本信息】 吉林大学 ， 材料学， 2012， 硕士

【摘要】 目前，临床上广泛应用的临床骨植入材料主要是不锈钢，钛和铬基合金。但是，这些材料密度大，与人体骨的弹性模量不匹配，造成应力屏蔽，而且属于重金属元素，难降解，需要二次手术取出，对人的身心健康造成不好的影响，而且二次手术加重经济负担。另一方面，这些金属材料密度大，其弹性模量与人体骨相差很大，造成应力屏蔽效应，对骨的生长产生不利的影响。当前，开始对镁合金作为骨植入材料进行研究。镁合金具有密度小，具有良好的力学性能，比强度高，与人体骨弹性模量接近，易降解性等优点。但是镁合金的化学性质活泼，耐蚀性不好，所以要提高它的耐蚀性。另一方面，要在镁合金表面镀一层具有生物活性的膜，促进骨生长。本论文采用钙系磷化液在镁合金AZ91表面制备具有生物活性的钙系磷化膜。采用控制变量法，在其它条件都不变的情况下，加入不同含量的间硝基苯磺酸钠、钼酸钠以及不同的pH值制备出磷化膜。采用扫描电镜观察磷化膜的表面形貌，极化曲线分析它的耐腐蚀性。得出结论，间硝基苯磺酸钠具有促进成膜的作用，但是含量过多的时候也影响成膜质量，影响耐腐蚀性。钼酸钠具有增加形核质点的作用，促进成膜，过多含量的钼酸钠在溶液中形成难溶的钼酸钙，降低钙离子含量，影响成膜。再次，通过实验研究证明，pH值对成膜也有极大的影响。当pH值为2.5以下时，膜的质量很差，由于酸度太大，镁合金腐蚀速度过快，成膜的速度小于腐蚀速度，使膜层覆盖不均匀,但是当溶液的pH过高的时候，成膜速度慢，导致晶粒粗大，影响膜层的耐蚀性能。经过以上实验得出最佳实验配方为氧化钙10g/L，磷酸60ml/L,硝酸钙10g/L,间硝基苯磺酸钠2g/L,钼酸钠1g/L,pH为3.0，温度40℃。采用能谱分析，得到膜层的化学成分，原子含量百分比，可以看出磷化膜的主要成分是钙系磷酸盐。采用xrd对膜层进行衍射分析，确定物相，得出膜的主要成分是磷酸钙。另一方面，本论文研究了磷化膜的成膜机理。在不同的反应时间下，10s，30s，60s，2min，5min，10min，20min，30min，得到膜层，对其进行扫描电镜观察，分析其显微组织，得出钙系磷化膜首先在β相上形成成核质点，逐渐向α相上扩展。刚开始时快速成膜阶段，然后经历缓慢成膜，最后超过30min时，磷化膜出现动态平衡阶段，镁基体腐蚀的速度和成膜的速度相平衡，对其耐腐蚀性也影响不大，所以最佳成膜时间是30min。更多还原

【Abstract】 At present, the clinical bone implant materials are mainly stainless steel, titaniumand chrome base alloy. But, these materials’ density, and elastic modulus don’tmatch with human bone.And because these materials belong to heavy metal，itcontains heavy metal elements,it’s bad to people’s health。. the refractory, need totake out a second time and need a surgery.It has bad effect to physical and mentalhealth and a second surgery increase economic burden. On the other hand, these metalmaterials’ density, the elastic modulus are very different from the human bone, and itcause stress shielding effect and make the growth of bone slowly. At present,magnesium alloy material began to have been used as bone implant for study.Magnesium alloy has the small density, good mechanical properties, high strength,close to human body bone elastic modulus, easily degradable, etc. But the chemiscalproperty of the magnesium alloy is live, the corrosion resistance is poor, so itscorrosion resistance needs to be improved. On the other hand, a layer of coating, onthe surface of magnesium alloys with biological activity of membrane can promotebone growth.This thesis is about preparing bioactive calcium phosphate film in the liquid ofcalcium phosphate on the surface of AZ91surface。The method is controlling thevariable. under the condition ovariable in other conditions constant, join differentcontents of nitrobenzene between sulfonic acid sodium, sodium molybdate and indifferent pH value the preparation phosphating film. With scanning electronmicroscopy (sem) of phosphating film surface morphology, polarization curveanalysis its corrosion resistance.The conclusion were that the difficulties betweensulfonic acid sodium can promote the role of film, but much more content alsoinfluence the quality of film, affect corrosion resistance. Sodium molybdate increasednuclear particle shape, promote the film。 too much of the content of sodiummolybdate in solution formed undissolved molybdenum acid calcium, reduce thecalcium ion content, affects the film. Again, through the experiment proves that the pH value of film also have the enormous influence. When the pH value of2.5thefollowing, the film’s quality was poor, the acidity because too big, magnesium alloycorrosion speed too fast, the speed of the film is less than the corrosion rate, make themembrane layer on the map.From the energy spectrum analysis, it’s included that the membrane of thechemical composition, and atom percentage content, the main components of thephosphate film is calcium phosphate. By XRD on membrane layer diffraction analysis,object is determined, it is concluded that the main components of the film is calciumphosphate.On the other hand, this paper studies the formation mechanism of phosphate film.In different reaction time,10s,30s,60s,2min,5min,10min,20min,30min, toget membrane layer, and carry on the scanning electron microscopy (SEM) of theanalysis of the microstructure, draw of calcium phosphate film first formed on thebeta phase into nuclear particle, α gradually to expand on that. It’s included that,phosphate film appear dynamic balance stage more than30min, magnesium matrixcorrosion speed and film speed phase equilibrium stage, the corrosion resistance andthe impact is not big, so the best film time is30min.更多还原