简介:Zincwasrecentlysuggestedtobeapotentialcandidatematerialfordegradablecoronaryarterystent.Thecorrosionbehaviorofpurezincexposedtor-SBFupto336hwasinvestigatedbyelectrochemicalmeasurementsandimmersiontests.Themorphologyandchemicalcompositesofthecorrosionproductswereinvestigatedbyscanningelectronmicroscope,grazing-incidenceX-raydiffraction,X-rayphotoelectronspectroscopyandFouriertransforminfraredspectrometer.Theresultsdemonstratethattheinitialcorrosionproductsonthepurezincmainlyconsistofzincoxide/hydroxideandzinc/calciumphosphatecompounds.ThepureZnencountersuniformcorrosionwithanestimatedcorrosionrateof0.02-0.07mmy^-1duringtheimmersion,whichsuggeststhesuitabilityofpureZnforbiomedicalapplications.
简介:Hydroxyapatite(哈,Ca10(PO4)6(哦)2)涂层被激光cladding技术在纯Ti(TA2)上制作。阶段结构,微观结构,microhardness和激光cladded的电气化学的行为哈在人工的身体液体的涂层被调查。HA涂层主要高度被创作的结果表演结晶哈。过渡的层在之间哈涂层和Ti底层被形成。Microhardness测量显示出逐渐地在过渡的层在TA2底层从150HVmicrohardness增加到600HV,并且由一减少到400HV在列在后面哈涂的层。电气化学的腐蚀测试证明HA涂层与TA2底层相比有更高开的电路潜力,更低的腐蚀水流密度和腐蚀率。
简介:在团结微观结构的谷物结构和precipitates极端纯有不同Ti或Nbmicro-alloying的17wt%Cr以铁酸盐为主要成的不锈钢试验性地并且理论上被调查。到钢的Ti或Nb的增加减少了谷物尺寸(D)和延伸因素(E),这被谷物结构观察发现,并且改进了equiaxed谷物比例(P)和球状因素()。在学习的四钢之中,最小的谷物尺寸和最大的equiaxed谷物比例被联合把Ti和Nb加到钢获得。SEM观察显示了那几种猛冲例如锡,MC(在Nb的富人),等等,洗阶段(Fe2Nb)在相应的钢形成了。另外,用Thermo计算软件计算的结果说明了那听在合适的Ti和N内容在液体猛抛。同时,团结间隔(T)被Ti或Nb的增加扩大,并且Nb的有效性比Ti强壮。基于试验性并且计算结果,在equiaxed谷物比例的谷物精炼和增长的机制被讨论。
简介:Anumberoftechniqueshavebeendevelopedtosynthesizenanocrystallinebulkmaterials,includinginert-gascondensationandconsolidation,electrodeposition,severeplasticdeformation,crystallizationofamorphoussolid,surfacemechanicalattrition,andpowdermetallurgy.However,itishardtoproducethebulkwithcontrollablenanostructures,especiallywiththegrainsizescontrollableinawiderangebelow100nm.Intheconventionalpowdermetallurgy,duetothefactthatrapidcoarseningoftheparticles...
简介:Micro-finesphericalpowdersarerecommendedforselectivelasermelting(SLM).However,theyaremostlyexpensiveduetothecomplexmanufacturingtechniqueandlowyield.Inthispaper,usinglowcosttreatedhydride-dehydride(HDH)Tipowders,commercialpureTi(CP-Ti)wassuccessfullyfabricatedbySLM.After4-hmilling,theresultingpowdersbecomenear-sphericalwithnoobviousangularity,andhaveoptimalflowabilitywiththeapparentdensityof1.64±0.02g/cm^3,tapdensityof2.10±0.04g/cm^3,angleofrepose40.11±0.09,andCarr'sindexof77.74±0.15.Themicrostructurewasdeterminedw让hfullacicularmartensitica'phase.TheCP-Ticanachievesuperiormechanicalpropertieswiththeultimatetensilestrengthof876.1±20.5MPaandelongationof(14.7±0.5)%,whichexhibitdistinctlycompetitivecomparedtotheas-castCP-TiorTi-6A1-4V.Excellentmechanicalpropertiestogetherwith让slow-costmakeSLM-fabricatedCP-TifrommodifiedHDHTipowdersshowpromisingapplications.
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