简介:60%whitecorundumusedforaggregate,5%aluminiumpowderforfixedadditionsand35%variousadditivesformatrixwerepreparedforspecimens1#,2#,3#.Theyweremixeduniformlywiththesuitableresinasabinderandpressedunderpressureof315tonforgingpress,thendriedat200℃for24h.Effectsofvariousadditiveson1500℃×2hcreeppropertiesofAl3CONreinforcedcorundumcompositewereresearched.Theexperimenalresultsshowthatcreepcoeffi-cientsofspecimens1#,2#,3#at1500℃×2hare1.4×10-4,-9.4×10-4,-22.6×10-4,respectively.CrushingstrengthoftheslideplateaddedwithsuitableadditiveAafterfiredat1500℃×3hreachesto225MPa,thecreeprateispositiveallthetimefrom0%to0.014%at1500℃for2h.Themicro-structureresultanalysisshowsthatreinforcedphasesofAl3CONfibercompositehavebeenformedafterfiredwithAlpowderincokeathightemperaturesforspecimen1#,andthestrengthofthecompositeisincreased.Thehotmodulusofruptureisupto59MPaat1400℃andtheRULisobvi-ouslyhigherthanthatat1700℃.ItsservicelifeistwotimesasthatofAl2O3?Cslideplatewhenusedintheprocessofpouringsteel.Themechanismofcreeprateresistanceofthecompositescanbedis-coveredbymeansofSEMandEDAXanalysis.ItisconcludedthattheactiveAl3CONandAl2O3multiphasesthatwereformedbyN2ingas,C,AlandAl2O3insidethematrixofthecompositesduringin-situreaction,whichgivesthecompositesoutstandingcreeprateresistanceforthedensezonere-sultingfromAl3CONoxidationthatinhibitscontractionatthehightemperature.Besides,thematrixwillturnintothemultiphasewithhighrefractoriness,NcontentanditsAl3CONreinforcedfiberwillfurtherincreaseaccordingly.Inaddition,Al3CONformedbyAl2O3andC,AlinthematrixwithN2ingaswillinhibitthecreeprateandalsogreatlyimprovethecreeprateresistanceofthecomposites.
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简介:ThedensityofNi-Alalloysinbothliquidstateandsolid-liquidcoexistencestatewasmeasuredwithamodifiedpycnometricmethod.ItwasfoundthatthedensityofNI-AlalloysdecreaseswithincreasingtemperatureandAlconcentrationinthealloys.ThemolarvolumeofliquidNi-AlbinaryalloysincreaseswiththeincreaseoftemperatureandAlconcentration.ThepartialmolarvolumeofAlinNI-Albinaryalloywascalculatedapproximately.ThemolarvolumeofliquidNI-Alalloydeterminedinthepresentworkshowsanegativedeviationfromtheideallinearmolarvolume.
简介:纵的张力的性质原文如此有不同纤维体积部分的f/Ti-6Al-4Vcomposites被蒙特卡罗2-D模仿有限元素模型。纤维力量的随机的分发被二参数的Weibull功能表示。同时,接触元素和出生死亡元素被用来在debonding和纤维破裂以后描述界面的滑动过程(或矩阵裂开)分别地,它被子程序认识到在ANSYS-APDL(ANSYS参量的设计语言)应允了。试验性的结果证明收益应力和最终的张力的强度原文如此有增加的f/Ti-6Al-4Vcomposites增加纤维体积部分,当他们的相应紧张只是时相反。另外,几乎,一样的失败模式被获得在原文如此有各种各样的纤维体积部分的f/Ti-6Al-4Vcomposites什么时候界面砍力量被修理。最后,张力的力量由有限元素预言了分析与由全球分享负担的模型,预言了那相比本地人分享负担的模型和混合物的常规统治,因此画结论那个本地分享负担的模型为最终的张力的力量的预言是很完美的。
简介:TheatomicscalecomputersimulationforinitialprecipitationmechanismofNi75Al6V19alloywascarriedoutforthefirsttimebyemployingthemicroscopicdiffusionequation.Theinitialprecipitationprocesswasinvestigatedthroughsimulatingtheatomicpicturesandcalculatingtheorderparametersofthetwokindsoforderedphases.Simulationresultsshowthattheγ′orderedphaseprecipitatedearlierthanθorderedphasebycongruentordering+spinodaldecompositionmechanismandthusproducedanonstoicheometricγ′singleorderedphase.Then,thenonstoichiometricθphaseprecipitatedbyanon-classicalnucleationandgrowthmechanismattheAPBSofγ′phase.
简介:用organo听Sn(OC4H9)4作为先锋,钠dodecylsulfonate(SDS)和SDS明胶(SDS-G)象模板复杂,二听二氧化物胶体的粒子被准备由一自己组装方法。两个SnO2产品分别地与SDS-G与SDS和SnO2-C粒子被标记SnO2-B粒子,它在制作相应于SnO2-B和SnO2-C传感器的SnO2煤气的传感器被使用。X光检查衍射(XRD),扫描电子显微镜学(SEM),传播电子显微镜学(TEM)和thermogravimetry和不同热分析(TG/DTA)被用于描述。试验性的结果证明SnO2-B胶体的粒子由mesoporous组成像片的粒子,当SnO2-C粒子主要由球形的粒子组成时。煤气的察觉到大小证明那个SnO2-B传感器执行察觉到反应到所有目标气体的最好,包括H2,C2H5OH和液体石油气体(LPG)。特别地,SnO2-B传感器的察觉到的反应在1000潩獮的集中在H2空气在32点被完成
简介:利用喷射沉积工艺制备Al-3.3Fe-10.7Si合金坯,经挤压制成试样。研究了合金组织、韧性及内耗行为,得出该合金在60-250℃温度范围产生的内耗峰,是由于晶界滑动弛豫引起的,弛豫过程激活能为172.2kJ/mol。在内耗峰位置晶界滑动消耗部分振动能,合金韧性在此处出现极大值。
简介:血浆合金Zr和血浆nitriding的一个双处理被用来改进Ti-6Al-4V的tribological性质。Zr-N的微观结构合成(alloyed)层在Ti-6Al-4V和它的坚硬上形成了,磨擦并且穿性质被使用OM,SEM,GDOES,版本,microhardness测试者以及ball-on-disk摩擦计调查。微结构分析的结果证明alloyed层紧缩、一致并且主要由ZrN,听0.3和AlN组成。很微小的粘合剂和细微氧化穿的A是主要为修改Ti-6Al-4V穿机制。tribological性质在双处理以后显著地被改进。防摩的好联合并且穿抵抗因为修改Ti-6Al-4V主要被归因于在表面上形成并且提高了传播Zr层支持的金属氮化物的更高的表面坚硬。
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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:综述了原位合成Al3Ti/Al和Al3Ti/Mg基复合材料的研究现状。重点介绍了原位合成Al3Ti的反应体系、复合材料的制备方法及微观组织特点,指出了原位合成Al3Ti/Al和Al3Ti/Mg基复合材料在目前研究中所存在的主要问题及今后的研究方向。
简介:Themicrostructureevolutionandphasecompositionofanα+βtitaniumalloy,Ti-3Al-5Mo-4.5V(wt.%),havebeeninvestigated.Electronprobemicroanalysis(EPMA)quantitativeresultsmanifestthatthestabilityofβphasedecreaseswithincreasingquenchingtemperature,whichisinfluencedbythesignificantvariationofβ-stabilizingelementsconcentration.Detailedmicrostructureanalysisshowsthattheβ→ωphasetransformationdoesoccurwhenquenchingat750℃and800℃.Theω-reflectionschangefromincommensurateω-spots(750℃)toidealω-spots(800℃)astheβstabilityofthealloydecreases.Furtherthedecreaseofβphasestabilityencouragestheformationofathermalα"martensite,whichhasthefollowingorientationrelationships:[111]β//[110]α",[100]p//[100]α"and[-110]p//[00-1]α"withrespecttotheβmatrix.
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简介:ThemicrostructureandcompositionofTiC-Al2O3/Fefunctionallygradedmaterials(FGM)preparedbyself-propagatinghightemperaturesynthesisandpseudo-hotisostaticpressing(SHS/PHIP)werestudied,andtheresistingthermalshockbehaviorswereanalyzed.TheresultsshowthatTiC-Al2O3/FeFGMhasgradedcompositiondistribution.Nocross-sectioncrackthroughthelayerswasfoundinthetestsofthermalshockandfatigue.
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。