简介:从同样渗出的镁合金Mg-3%Al-1%Zn(AZ31)营舍准备的样品在低周期的疲劳测试被利用以便调查频率依赖者疲劳生活。充分颠倒的控制紧张的紧张压缩疲劳测试在空中在1Hz和10Hz的频率被执行。微观结构被光显微镜学(OM)和扫描电子显微镜学(SEM)检验。当紧张振幅比0.2%低时,疲劳生活与装载频率展出了积极关联,并且twinning的活动在10Hz被增加。当紧张振幅比0.2%高时,重要twinning在生活被发现独立于频率的这二频率,和疲劳被观察。为这频率相关的疲劳一生的可能的原因可能由于在装载频率和紧张振幅之上的twinning的依赖。
简介:这评论调查Mg和Mg合金的当前的申请限制。妨碍是的可被细菌破坏的Mg合金的申请的关键问题植入是他们的快降级率和生物考虑。我们在基于Mg的合金的性质上讨论了一些选择alloying元素增加的效果,特别在人的滋养的元素(Zn,Mn,Ca,Sr)。不同谷物尺寸,阶段成分和分布因而影响Mg合金的机械性质。溶液加强并且降水加强被alloying元素的增加提高,通常改进机械性质。而且,热工作过程能也改进机械性质。不同的处理的步的联合被建议在基于Mg的合金的制造被收养。这些基于Mg的合金的腐蚀性质在vitro并且在vivo被测量了。降级机制也以包围纸巾的腐蚀类型,率,副产品和回答被讨论。而且,临床的反应和要求可能减解植入被介绍,特别为滋养的元素(Ca,Mn,Zn,Sr)。这评论提供与不同Mgalloying元素有关的信息并且介绍答应理想的候选人植入。
简介:Al-Cu-Mg系铝合金具有较高的强度和良好的耐热性能,被广泛用于航空航天材料。微量Ag、Li的添加及复合添加能够改善Al-Cu-Mg系合金的性能,而析出相对合金的性能起决定作用。介绍了微量Ag、Li的添加及复合添加对Al-Cu-Mg合金析出相的影响,重点分析了不同析出相的结构特征、形成条件以及析出序列,并提出了存在的问题及应用前景。
简介:微弧的氧化(毛)/zinc硬脂酸盐(ZnSA)合成涂层经由毛与superhydrophobicZnSA的电极淀积处理并且随后的封上被制作。表面形态学,化学作文和涂层的腐蚀抵抗用扫描电子显微镜学的地排放被调查,Fourier变换红外线,X光检查衍射并且电气化学并且氢进化大小。结果显示毛涂层被下列superhydrophobicZnSA涂层高效地封上。MAO/ZnSA合成涂层显著地由于它的superhydrophobic功能提高了Mg合金Mg-4Li-1Ca的腐蚀抵抗。另外,腐蚀机制为合成涂层被建议并且讨论。
简介:Energy-storageweldingconnectioncharacteristicsofrapidlysolidifiedAZ91DMgalloyribbonswith40~70μmthicknessareinvestigatedusingamicrotypeenergy-storageweldingmachine.Themicrostructureandperformanceoftheconnectionjointsareanalyzedandstudied.Theresearchresultsindicatethatenergy-storageweldingisabletorealizethespotweldingconnectionofAZ9lDMgalloyribbons.Theweldingnuggetconsistsofdevelopedα-Mgequiaxedgrainswiththesizesof1.2~2.7μmandintergranulardistributedβ-Mg17Al12compounds.Thethicknessofbondzoneisabout4μmandthesolidificationmicrostructureischaracterizedbythefineequiaxedgrainswiththesizesof0.8~1.2μm,andgrainboundaryhasbecomecoarsening.ThecolumnarcrystalinHAZalsobecomesslightlycoarseningandthegrainboundaryhasbroadened,however,thereisnoobviouschangeinitsprimitivemorphologyandcrystallographicdirection.Whenweldingenergyisabout2.0J,theweldingjointswithhighershearstrengthandsmallerelectricalresistivityareobtained.
简介:由热退火的非结晶的Mg65Cu25Gd10合金和结构的变化的本地原子结构被扩大X光检查吸收罚款结构(EXAFS)学习了。在为Mg65Cu25Gd10合金的结构的变化和机械性质之间的关联也被讨论了。结果证明在在Mg65Cu25Gd10的Gd附近的Cu原子在退火期间很快输了,导致Cu原子的分离。Mg65Cu25Gd10的协作数字NGd-Mg首先在373K退火了减少然后随退火的增加扩充了时间。形成多面短期顺序在Gd原子附近与将近12的协作数字联合起来赞成机械性质的改进。化学药品短期顺序,不是拓扑短期在非结晶的Mg65Cu25Gd10合金的顺序在退火期间有明显的变化。
简介:Anas-castmagnesiumalloywithhighAlcontentMg15Alwassubjectedtoequal-channelangularpressing(ECAP)throughadiewithanangleofφ=90?at553KfollowingrouteBc.Itisfoundthatthenetworkβ-Mg17Al12phasesintheas-castMg15Alalloyarebrokenintosmallblocksanddisperseduniformlywithincreasingnumbersofpressingpasses.Moreover,manynano-sizedMg17Al12particlesprecipitateintheultra-fineα-Mgmatrix.Thegrainsareobviouslyrefined.However,thegrainstructureisinhomogeneousindifferentareasofthealloy.Theaveragesizeoftheprimaryphaseα-Mgisreducedtoabout1μmwhilegrainsofaround0.1-0.2μmareobtainedinsometwo-phaseareas.WithadditionalECAPpasses(upto8),coarseningofthegrainsoccursbydynamicrecovery.RoomtemperaturetensiletestsshowthatthemechanicalpropertiesofMg15Alalloysaremarkedlyimprovedafter4ECAPpasses.Theultimatetensilestrengthandelongationtofailureincreasefrom150MPato269.3MPaandfrom0.05%to7.4%,respectively.Comparedwiththatafter4passes,theelongationtofailureofthealloyincreasesbutthestrengthofthealloyslightlydecreasesafter8ECAPpasses.FracturemorphologyoftheECAP-processedalloyexhibitsdimple-likefracturecharacteristicswhiletheas-castalloyshowsquasi-cleavagefractures.
简介:Thedeformationmechanismsandprocessingmapsoftheas-castAl-Zn-Mg-Cu(7075)aluminum(Al)alloywerestudiedandcomparedwiththoseofthehomogenized7075Alalloyinthetemperaturerangeof573–723Kandinthestrainraterangeof10~(-3)–10s~(-1)toexploreapossibilityfordirectlyusingtheascast7075Alalloyasabilletforhotworking.Theas-castandhomogenized7075Alalloyshadsimilargrainsizesandshowedsimilarhigh-temperaturedeformationbehaviors.Theas-cast7075Alalloy,however,exhibitedhigherpowerefficienciesandsmallerunstable?owregionscomparedtothehomogenized7075Alalloybecauseofthepresenceofsecondaryphases(MgZn_2)segregatedatthedendriticinterfacesintheas-castmicrostructure,whichwereformedduringnon-equilibriumsolidi?cation.Thesesegregatedphasesprovidednucleationsitesfordynamicrecoveryorcontinuousdynamicrecrystallization,andasaresulta?neandmorehomogeneous(sub)grainstructurecouldbeobtainedfromtheas-castmicrostructurecomparedtothehomogenizedmicrostructure.Thecurrentworksuggestedthepossibilityandadvantageofusingas-castmicrostructuresforhotworkingofaluminumalloyswithhighcontentofsolutes.
简介:biomagnesium合金被认为由于它的好机械相容性,生物相容性,生物安全和可被细菌破坏的特征是最潜在的可被细菌破坏的金属材料之一。然而,在生理的环境和低机械性质的高降级率的二个主要问题阻止biomagnesium合金的发展。在现在的工作,Mg-Zn-Y-Nd合金的样品被周期的挤出压缩(CEC)和相等的隧道准备尖紧迫(ECAP)。微观结构,合金的机械性质和它在模仿的身体液体(SBF)的腐蚀行为被评估。结果表明那Mg-Zn-Y-Nd合金与测微计尺寸和缩放nano的秒阶段的同类的分发由equiaxial罚款谷物结构组成,它被动态再结晶在ECAP和CEC期间引起。合金的腐蚀抵抗被改进。张力并且腐蚀抵抗被改进,特别处理合金展览制服腐蚀表演和减少的腐蚀评价。这将作为脉管的stent申请为Mg-Zn-Y-Nd合金提供理论地面。
简介:TheevolutionofmicrostructureandmechanicalpropertiesofAl-0.4Cu-0.14Si-0.05Mg-0.2Fe(wt.%)alloys,micro-alloyedwithZr,TiandSc,wereinvestigated.Theadditionof0.2%ZrtobasealloyacceleratestheprecipitationofSi-richnano-phaseinα-Almatrix,whichplaysanimportantroleinimprovingthemechanicalpropertiesofanalloy.Thetensilestrengthincreasesfrom102MPaforthebasealloyto113MPafortheZr-modifiedalloy.Adding0.2%Zr+0.2%Titobasealloyeffectivelyrefinesa-AlgrainsizeandacceleratestheprecipitationofSiandCuelements,leadingtoheavysegregationatgrainboundary.Byfurtheradding0.2%SctoZr+Timodifiedalloy,thesegregationofSiandCuelementsissuppressedandmoreSiandCuprecipitatesappearedinα-Almatrix.AccompaniedwiththeformationofcoherentAl3Scphase,thetensilestrengthincreasesfrom108MPafortheZr+Timodifiedalloyto152MPafortheSc-modifiedalloy.DuetoexcellentthermalstabilityofAl3Scphase,theSc-modifiedalloyexhibitsobviousprecipitationhardeningbehaviorat350℃,andthetensilestrengthincreasesto203MPaafterholdingat350℃for200h.
简介:Throughmeasuringthecoefficientoflinearexpansion,thestructureandpropertiesoftheLi2O-Al2O3-SiO2lowexpansionglassceramicscontainingB2O3arestudiedbyJRandXRD.ItisshoutnthattheIRmethodisefficientinthestudyoftheglass-ceramicsstructure.Thereisa"Boronabnormality"inthesystemwhichhasanimportantinfluenceonthepropertiesoftheglass-ceramics.
简介:TheelectronicstructuresofCuS2,CuSe2andCuTe2withpyritestructures,withintheframeworkthedensity-functionaltheoryhavebeeninvestigated.ThecalculatedresultsexplainedtherecentexperimentalresultswhichshowthatthereisnoclearindicationofstrongelectroncorrelationsintheelectronicpropertiesofCupyrites,duetothedominantchalcogenpcharacterratherthandcharacteristicofCuattheFermilevel.