简介:这个工作的目的是用电气化学的技术,光显微镜学,扫描电子显微镜学(SEM),和精力与氟化物离子在酸的人工的口水为牙齿的应用学习Ti-6Al-4V合金的降级行为散的spectrometry(版本)。试验性的结果证明那个氟化物离子在Ti-6Al-4V合金的降级上有重要影响,并且有氟化物离子(大约0.1wt%)的明显的批评集中。与增加氟化物离子集中,腐蚀潜力(E合金的corr)移动了向否定并且同时,合金的阻抗减少了到严重pitting腐蚀的从最小的腐蚀的显著转变在跟随TiO2的溶解的合金表面上被观察被动电影,导致合金的腐蚀抵抗的减少。TiO2的电气化学的溶解被动电影包含了氟化物原子的亲核的攻击到TiO2的钛原子。另外,在酸的口水的Ca2+和Na+可以包含表面反应并且使反应更复杂。
简介:一个双网络模型被建立,它由片断,E和A成分链组成,与另一个纠缠由的聚合的链多--纠纷和聚合的链由多吸附与很多右破坏的粒子连接了,基于哪个E和A成分链能动态地被再创造并且释放。端对端的向量的分发功能,为在多纠纷和多吸附状态和他们聚合的链的数字的二种链的符合构造的统计分发功能被统计力学和动力学的联合计算。然后,为二种网络和暂停的变丑的粘弹性的免费精力被Boltzmann的统计理论计算。另外,为二种网络和暂停的有弹性的模量和存储器功能被导出。因而,为聚合暂停的非线性的粘弹性的一个新分子的理论被建议,并且有在不同流动地里为聚合暂停让步并且变瘦的组成的方程和材料功能从理论被导出。(编辑作者摘要)15个裁判员。
简介:AdditivelymanufacturedTi-6Al-4Vlatticestructureshavefoundimportantnicheapplications.However,theyoftenshowinsufficientcompressiveductilityorinsufficientstructuralintegrity.Inthisstudy,abatchof45octahedralTi-6Al-4Vlatticestructureswasmanufacturedinthreedifferentstrutdiameters(0.5,1.0,1.5mm)byselectiveelectronbeammelting(SEBM).Theinfluenceofpost-SEBMannealingonthecompressivedeformationcharacteristicsofthelatticestructurewasinvestigated.Theas-builtTi-6AI-4Vlatticesfragmentedwhenthecompressivestrainreached13%-23%dependingonstrutdiameter.Annealingat950℃(Ptransustemperature:995℃)onlyslightlyimprovedthecompressiveductilityofthelatticestructures.However,annealingat1050℃(p-annealing)fundamentallychangedthecompressivedeformationmodeofthelatticestructures.Theresultantcompressivestress-straincurvewasfeaturedbyalongsmoothplateauandnofactureoccurredevenaftersignificantdensificationofthelatticestructurehadtakenplace(>50%ofcompressivestrain).
简介:
简介:
简介:Anovel,Ti-6A1-4V(Ti64)/Hydroxyapatite(HAat5%byweightconcentration)metal/ceramiccompositehasbeenfabricatedusingelectronbeampowderbedfusion(EPBF)additivemanufacturing(AM):specifically,thecommercialelectronbeammelting(EBMR)process.InadditiontosolidTi64andTi64/5%HAsamples,fourdifferentunitcell(model)open-cellularmeshstructuresfortheTi64/5%HAcompositewerefabricatedhavingdensitiesrangingfrom0.68to1.12g/cm^3,andcorrespondingYoung'smodulirangingfrom2.9to8.0GPa,andcompressivestrengthsrangingfrom-3to11MPa.ThesolidTi64/5%HAcompositeexhibitedanoptimaltensilestrengthof123MPa,andelongationof5.5%incontrasttoamaximumcompressivestrengthof875MPa.Boththesolidcompositeandmeshsamplesdeformedprimarilybybrittledeformation,withthemeshsamplesexhibitingerratic,brittlecrushing.Solid,EPBF-fabricatedTi64sampleshadaVickersmicroindentationhardnessof4.1GPawhiletheTi64/5%HAsolidcompositeexhibitedaVickersmicroindentationhardnessof6.8GPa.ThelowestdensityTi64/5%HAcompositemeshstrutsectionshadaVickersmicroindentationhardnessof7.1GPa.Opticalmetallography(OM)andseanningelectronmicroscopy(SEM)analysisshowedtheHAdispersoidstobehighlysegregatedalongdomainorgrainboundaries,buthomogeneouslydistributedalongalpha(hcp)plateletboundarieswithinthesedomainsintheTi64matrixforboththesolidandmeshcomposites.Thealphaplateletwidthvariedfrom-5μmintheEPBF-fabricatedTi64to-1.1μmfortheTi64/5%HAmeshstrut.TheprecursorHApowderdiameteraveraged5μm,incontrasttothedispersedHAparticlediametersintheTi64/5%HAcompositewhichaveraged0.5μm.ThisworkhighlightstheuseofEPBFAMasanovelprocessforfabricationofatruecompositestructure,consistingofaTi64matrixandinterspersedandexposedHAdomains,whichtotheauthorsknowledgehasnotbeenreportedbefore.Theresultsalsoillustratetheprospectsnotonlyforfabrica
简介:
简介:Three-dimensional-printed(3D-P)titaniumimplantsdisplaymanyadvantages,suchasdesignflexibility,higherefficiency,thecapabilitytoeasilyconstructcomplexorcustomizedstructures,etc.,andisbelievedtopotentiallyreplacetraditionalimplants.However,thebiologicalperformanceofthe3D-Ptitaniumsurfacehasnotbeeninvestigatedsystematically.Herein,weanalyzedthesurfacecharacteristicsof3D-PTi6AI4Vimplantsandevaluatedthebiologicalresponsesofbonemarrowderivedmesenchymalstromalcells(BMSCs)tothe3D-Psurfaceinvitro.Moreover,afterimplantationintotheratfemoralcondylefor3and6weeks,theosseointegrationperformaneewasevaluated.Theresultsshowedthe3D-PTi6Al4Vimplantpresenteddistinctfluctuantmacroscaleroughsurfaceandrelativelybetterhydrophilicitywhichenhancedtheadhesion,proliferation,osteogenicdifferentiationandangiogeneticfactorexpressionofBMSCs.Moreover,theinvivoosseointegrationperformancewasalsobetterthanthatofthecontrolgroupattheearlystage.Thepresentstudysuggestedthe3D-Ptitaniumalloyisapromisingcandidatetobeusedasimplantmaterial.
简介:来临三维(3-D)打印了技术在设定的多孔的钛(Ti)的制造提供大可能性植入。然而,打印Ti的bioinert性质提出一个突出的问题。混合微弧的氧化并且热水(MAO-HT)多孔的金属上的处理能生产multi-scaled层次矫形植入,为3-D的表面修正的出现大潜力打印了植入。在这研究,有毛孔的圆柱的多孔的Ti6Al4V(Ti64)脚手架640缩放吗??