超音速氧焰喷涂羟基磷灰石涂层的研究

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1、西南交通大学硕士学位论文超音速氧焰喷涂羟基磷灰石涂层的研究姓名：鲍益富申请学位级别：硕士专业：生物医学工程指导教师：翁杰20090501西南交通大学硕士研究生学位论文第1l页针对涂层在模拟体液中发生剥落的问题，本文采用在HA涂层表面涂覆聚乳酸(PLA)的方法改善其在水溶液中的稳定性。考察了不同浓度及涂覆次数对涂层稳定性的影响。实验发现，涂层表面涂覆聚乳酸后，在水溶液中的稳定性增强，因为疏水的聚乳酸可以防止水渗入涂层。超声过程中涂层表面以点状方式掉落，与涂层表面聚乳酸膜存在微小的孔洞有关。涂覆浓度及次数对涂层的影响较为明显，浓度低时，涂层易掉落。涂覆次数少，薄膜易破裂，涂覆次数多了，涂层与薄膜问

2、的结合强度降低，导致两者整体分离。本文认为39／100ml的浓度，涂覆次数以三次为佳。lg／100ml时，涂覆五次效果要好于三次。关键词：超音速氧焰喷涂；羟基磷灰石；颗粒状态；生物玻璃：聚乳酸西南交通大学硕士研究生学位论文第1II页AbstractHydroxyapatite(

3、Lqcoatingsdepositedontitaniumalloysubstratesusingairplasmaspray(ASP)isbeingwidelyusedinmedicalboneprosthesesandsubstitutions．However，duetotheextremelyhightemper

4、atureoftheplasmajet，thebondstrengthislow，andthedegradationofHAinvolvestheformationoftricalciumphosphate(TCP)，tetracalciumphosphate(TTCP)willcausethecoatingdissolutionanddesquamation．Hi曲volecityoxy-fuel(HVOF)sprayhasextraordinaryhighparticlevelocityandcomparativelylowtemperatureandcallbeanappropriate

5、methodtoproduceHAcoating．HAcoatingswaspreparedbyHVOFandtheeffectsofthreeflowratesonthepropertiesofphasescomposites，meltingstateofsprayedHAparticlesandsurfacemorphologyofcoatingswereinvestigatedinthispaper．TheresultsshowedthattheincreaseoffuelflowratescouldenhancethemeltingdegreeinthesurfaceofHAparti

6、cles，thecalculationofmeltfractionofHAparticlerevealedthatthemeltfractionincreasedalittlefrom12．79％to18．00％asthefuelraterisen．ThereasonisthatlargerflowrateresultinhighertemperatureoftheflameaswellasacceleratedthevelocityofHAparticlesandreducedthetimeofparticleduringintheflame．Qualitativephaseanalysis

7、withX-raydiffraction(XRD)showedthatthecoatingismainlycrystallineHAandthecrystallinityofHAdecreasedfrom91．4％t073．8％whentheflowratesincreased，itiscausedbythedifferentmeltfractionbetweentheHAparticles．Asthescanningelectronicmicroscopy(SEM)observationshown，HVOFsprayedcoatingsexhibitedthreetypicalmorphol

8、ogiesandmicrostructuresaftertheHAparticlesimpingedonthesubstrates．西南交通大学硕士研究生学位论文第lV页HA／bioactiveglass(BG)coatingswereproducedtOimprovethebioactivityofthecoating．TheeffectofBGadditiononpropertiesofas-