学科分类
/ 25
500 个结果
  • 简介:ThenanostructuredAl-basedcompositespossessthecombinationofhighyieldstrengthandgoodductility.Inthispaper,amicromechanicalmodelispresentedtosimulatethemechanicalresponseofbimodalnanostructuredAlandtheparticle-reinforcedaluminummatrixcomposite(PAMC).Theconstitutiverelationsfordifferentphasesareaddressedinthemodel,aswellasthecontributionofmicrocracks.NumericalresultsshowthatthemodelcansuccessfullydescribetheenhancedstrengthandductilityofthebimodalnanostructuredAl,andthepredictionsofthePAMCareingoodagreementwiththeexperimentaldata.ItisworthnotingthatthestrengthandductilityaresensitivetothevolumefractionofconstituentsandthedistributionofmicrocracksinbothbimodalnanostructuredAlandPAMC.Therefore,thepresenttheoreticalresultscanbeusedtooptimizethemicrostructureforimprovingthemechanicalpropertiesofnanostructuredAl-basedcomposites.

  • 标签: 颗粒增强铝基复合材料 屈服强度 纳米材料 细观模拟 聚丙烯酰胺水凝胶 塑性
  • 简介:WehavecarefullyreadDr.Yuandhiscolleagues'~1reviewonthemechanismofhamstringmusclestraininjuryinsprinting.Thereisnodoubtthattheyhavedonealotworkinthisfield.Theirviewsarebasedon3piecesofevidence.First,observationsfrominsituanimalmodelssuggestthatmusclestraininjuriesarehighlyassociatedwitheccentriccontractions.Second,themagnitudeofmusclestrain,ratherthantheforce,is

  • 标签: 肌肉 拉伤 机制 评论 危险因素 动物模型
  • 简介:Themicrostructureandslagerosionfractaldimensionofreactioninterfaceofβ-Sialon-Al2O3brickusedin300MtironladleofBaosteelhavebeenstudiedbySEMandXRD.Theresultsindicatedthatβ-Sialon-Al2O3brickexhibitedexcellentslagresistance.Themainwearmechanismofβ-Sialon-Al2O3brickismainlyfromthespallingcausedbythermalmechanicalstressandattackedbyslagsecondly.

  • 标签: 耐火材料 三氧化二铝 制备 β-硅铝氧氮聚合材料 石英砖 显微结构
  • 简介:Al2O3-MgOcastableshavebeenwidelyusedforworkingliningsofsteelladleduetotheirsuperiorhotstrengthandcorrosionresistance.Inthiswork,effectsofmicrosilica,ultrafinealuminaandMgOfinesadditionsontherheologicalbehaviorofthecastableswereinvestigatedbymeansofIBBrheometerV1.0tomeasuretorque(shearstress)undervaryingshearrates.Theresultsshowthatrheologicalpropertiesofcastablesatvaryingshearratesaresignificantlyimprovedwithincreaseofmicrosilicaadditions(from1mass%to5mass%)andcorrespondingdecreaseinwateraddition;thereisonlylittlechangeinrheologicalbehaviorwithvariationofultrafinealuminaandMgOfinesadditions.Optimumultrafinealuminaandmicrosilicaadditionsarerecommendedforcastableswithgoodrheologicalbehavior.

  • 标签: 超细氧化铝 流变行为 浇注料 氧化镁 水泥 剪切速率
  • 简介:用粒度为63μm和14μm的SiC粉末为原料,在注射温度和注射压力分别为160℃和70MPa、粉末装载量(体积分数)为63%的条件下,获得SiCp注射坯,经过溶剂脱脂和真空热脱脂以及1100℃/7h的真空预烧结后,在1000℃、N2气氛下进行Al合金熔渗,制备高体积分数63%SiCp/Al复合材料电子封装壳体。研究表明,熔渗组织均匀、致密,SiC颗粒均匀分布在Al基体中。熔渗时需要严格控制熔渗时间,熔渗时间超过10min后会导致坯体被Al合金熔体过度熔渗,从而在复合材料表面产生Al合金层,时间越长,Al层厚度逐渐增加。最终制得的高体积分数63%SiCp/Al复合材料封装壳体的尺寸精度优于0.3%,其热物理性能优异,热膨胀系数和热导率分别为7.2×10-6K-1和180W/m·K,密度为3.00g/cm3,能够满足电子封装材料性能的要求。

  • 标签: SIC/AL复合材料 电子封装 粉末注射成形 熔渗
  • 简介:摘要本文通过分子动力学方法对液态Ti-Al合金的扩散进行模拟研究,通过计算体系中原子的MSD曲线得到随着温度的升高,扩散系数增大,说明温度越高,原子越容易移动扩散,此结论与热力学理论相吻合,即温度越高,体系的能量越大,平均每个原子的能量也就越大,原子就容易移动,即扩散也会增加,体现在扩散系数上的增大。

  • 标签: 分子动力学模拟 液体金属 扩散 MSD
  • 简介:ArapidlysolidifiedAl-2.5Ti-2.5Fe-2.5Cr(massfractionin%)alloywaspreparedbymeltspinning.Asquenchedandas-annealedmicrostructureswerestudiedbyX-raydiffractometry(XRD),transmissionelectronmicroscopy(TEM),high-resolutiontransmissionelectronmicroscopy(HREM)andenergydispersivespectrum(EDS)analysis.Themicrohardnessofthealloyatdifferentannealingtemperatureswasmeasured.TheresultsobtainedindicatethatthemicrohardnessoftherapidlysolidifiedAl-2.5Ti-2.5Fe-2.5Cralloydoesnotvarywithdifferentannealingtemperatures.Theas-quenchedmicrostructureofthealloyincludestwokindsofdispersedprimaryphases:Al3TiandAl13(Cr,Fe)2.Afterannealingat400℃for10h,thestablephaseAl13Fe4appearsinthemicrostructure.

  • 标签: Al-Ti-Fe-Cr合金 微结构 热稳定性
  • 简介:Thecorrosionbehaviorandanti-corrosionmechanismoftheZn-Ni-Al2O3compositecoatingwereinvestigatedbySEM,EDSandXPS.TheresultsindicatethatthecorrosiontypeoftheZn-Ni-Al2O3coatingsinneutral5wt.%NaClsolutionisuniformcorrosion.ThepresenceofcompactanduniformlydispersednanoaluminaparticlessubstantiallyinhibitsthecorrosionofZn-Ni-Al2O3compositecoatings.Intheinitialcorrosionstage,thecorrosiveproductsofZn-NimatrixformacompactZnCl2·4Zn(OH)2layer.Withthedevelopmentofcorrosion,somenanoaluminaparticlesareembeddedandformaNienrichmentlayer.InNienrichmentlayer,NipresentsasNiandNiO.

  • 标签:
  • 简介:Theeffectsofconcurrentpulsesinholdingdurationonsuperplasticityof2091Al-Lialloyhavebeeninvestigatedinthispaper.Theresultsofsuperplasticdeformationshowedthatconcurrentpulsesinholdingdurationdecreasedtheoptimumholdingtimeforsuperplasticdeformation(ε=3.33×10-2s,T=500℃)from15to5minandincreasedelongation(δ)from530to550%.Themetallographicobservationsshowedthatthespecimensappliedlybyconcurrentpulsewerecom-pletelyrecrystallizedafterholding5minat500℃,andgrainsrefinedtoabout2μm,andthosespec-imensunappliedcurrentpulseswerepartlyrecrystallizedevenafterholding15minat500℃.theelectronprobeanalysesindicatedthatconcurrentpulsespromotedatomicdiffusion.Itispointedoutthatconcurrentpulsesaccelerateatomdiffusionanddislocationmotion.increasenucleationrateofrecrystallizationanddecreasetheoptimumholdingtimeforsuperplasticdeformationandincreasesuperplasticproperties.

  • 标签: current PULSE SUPERPLASTICITY RECRYSTALLIZATION
  • 简介:TheinfluencesoffourkindsofadditivesaddedintothematrixofMgO-Al2O3unbunedproductswereinvestigated,TheresultsshowthatsampleswithproperMgO/Al2O3rationandproperadditionofCr2O3(2%-4%)havegoodthermalshockresistanceandslagcorrosionresistanceaswell,XRDandSEMdeterminationresultsindicatethatakindofcompoundspinel(Mg,Al,Cr)O4wasformedandthemicrostuctureofthesamplesaredenser.

  • 标签: 添加剂 性质 氧化镁 三氧化二铝 三氧化二钴 耐火材料
  • 简介:以便得到TiB2-Al2O3的同质的混合物和协议,一个表面修正方法被用来准备nano规模的杂交Al2O3涂的TiB2粒子。PE蜡粒子是第一到由杂交,然后nano规模Al2O3粒子的TiB2粒子上涂又是涂的到由PE蜡粒子涂的TiB2的表面上。SEM,TEM和版本被用来描绘同样收到的核心/壳粒子和它的协议的微观结构。试验性的结果显示出那粒子规模TiB2和Al2O3的同质的分散能不仅在混合粉末而且在使脱蜡的协议被形成。协议当时是由煤气压的sintering(GPS)的sintered。物件顶端的装饰物产品显示出与参考样品由正常方法制作了作比较的改进技工性质。

  • 标签: 复合材料 AL2O3颗粒 TIB2 氧化铝涂层 制作 表面改性方法
  • 简介:PhasesandmicrostructuresofthreehighZncontainingAl–Zn–Mg–Cualloyswereinvestigatedbymeansofthermodynamiccalculationmethod,opticamicroscopy(OM),scanningelectronmicroscopy(SEM)energydispersivespectroscopy(EDS),X-raydiffraction(XRD),anddifferentialscanningcalorimetry(DSC)analysis.TheresultsindicatethatsimilardendriticnetworkmorphologiesarefoundinthesethreeAl–Zn–Mg–Cualloys.Theas-cast7056aluminumalloyconsistsofaluminumsolidsolution,coarseAl/Mg(Cu,Zn,Al)2eutecticphases,andfineintermetalliccompoundsg(MgZn2).Bothofas-cast7095and7136aluminumalloysinvolvea(Al)eutecticAl/Mg(Cu,Zn,Al)2,intermetallicg(MgZn2),andh(Al2Cu).Duringhomogenizationat450°C,fineg(MgZn2)candissolveintomatrixabsolutely.Afterhomogenizationat450°Cfor24h,Mg(Cu,Zn,Al)2phasein7136alloytransformsintoS(Al2CuMg)whilenochangeisfoundin7056and7095alloys.ThethermodynamiccalculationcanbeusedtopredictthephasesinhighZncontainingAl–Zn–Mg–Cualloys.

  • 标签: 铝锌镁铜合金 锌铝 显微组织 金属间化合物 扫描电子显微镜 差示扫描量热法
  • 简介:Inthepresentstudy,sampleswereextensivelycollectedthroughoutthestainlesssteelmanufacturingprocess.Thethree-dimensionalmorphologyofinclusionswasrevealedbynon-aqueoussolutionelectrolysis.Thehighconcentrationofaluminuminferrosiliconcausedtheincrementof[Al]sinsteelandAl2O3ininclusions,whichledtothehighermeltingtemperatureofinclusions.ItwasconcludedthattheapplicationoflowAlferrosiliconandcalciumtreatmentcouldpreventtheformationofAl2O3-richinclusions.

  • 标签: 奥氏体不锈钢 夹杂物控制 O3 低铝硅铁 水溶液电解 制造过程
  • 简介:研究了热处理制度和时效工艺的改变对Al-Zn-Mg系铝合金的组织结构、力学性能和应力腐蚀性能的影响.研究结果表明:高温预析出可以改变Al-Zn-Mg系铝合金晶界的析出相大小和分布,从而改善其抗应力腐蚀性能;在T6和T612种人工时效条件下,预析出的合金的抗应力腐蚀性能均好于无预析出的合金.在自然时效状态下,引入超声波,对无预析出合金的应力腐蚀性能进行了初步探索,发现超声波可以提高合金的抗应力腐蚀性能,而对合金的硬度无影响.

  • 标签: Al-Zn-Mg系铝合金 应力腐蚀 时效硬化 微观结构 超声 热处理
  • 简介:Fe-Ni-Almixturesashot-pressingsinteringadditivetoTitaniumdiboride(TiB2)werestudied.ItisfoundthatliquidalloyformedunderhightemperaturehardlyhaseffectsonthedensificationbehaviorsofTiB2-independent.Fe-Ni-AladditivejustworksasfillerbetweenTiB2particlesanddoesnotchangetheTiB2-independentsinteringbehaviors.PressingmodehasagreateffectontheliquidflowingbetweenTiB2particles.Multiple-stepspressingmodewillgivemoretimeandspacefortheliquidflowingandimprovetherelativedensityofTiB2-Fe-Ni-Alcermet.

  • 标签: 烧结行为 金属陶瓷 添加剂 TiB2粒子 液体流动 二硼化钛
  • 简介:透明的传导性的铝做了锌氧化物(ZnO:艾尔,偶氮)电影被rf(收音机频率)在玻璃底层上准备磁控管从ZnO劈啪作响:3wt%艾尔2O3陶器的目标。氩气体压力的效果(PAr)与小变化被调查在这些电影的电、光、结构的性质上理解影响。使用X光检查衍射(XRD)并且扫描电子显微镜学(SEM)的结构的考试证明ZnO:薄电影是的艾尔(002)面向。抵抗力价值被四点的探查与5.76穩摥甠楳杮愠?灯楴業敺?票牤瑯敨浲污洠瑥潨?倠牵?桰獡?景?㈱?眠獡朠瑯愠?的最低抵抗力测量?潣灭牡瑡癩汥?潬敷?整灭牥瑡牵?挨愮??‰??楳瑳?景漠敮?睴?琠牨敥?牯映畯?慬敹獲漠?敭慴?晲捡獥瀠慬散?湩琠敨渠慥?楦汥?敲楧湯漠??業牣獯牴灩瀠瑡档愠瑮湥慮?桔?湡整湮?慲潤敭猠獹整?慧湩椠?浩牰癯摥戠????潣灭牡摥琠?桴?慰'?湡整湮?污湯?愠摮琠敨爠摡慩楴湯瀠瑡整湲栠污?吗潰敷?敢浡楷瑤?獩爠摥'转棳_??L潳灲楴湯瀠慥獫眠牥?獡楳湧?敧愠敲?吠敨栠杩汨?晥楦楣湥?L潳灲楴湯漠?

  • 标签: 薄膜性能 溅射制备 磁控溅射 氩气压力 沉积薄膜 氧化锌