简介：AnewtypeofDZ9000EOxygenGaseousHVOFsystem(GHVOF)isdevelopedwhichcanreducethecostofcoatingsandincreasethein-situremovabilitytoadaptvariousworkingconditions.Thewholesystemiseconomical,whichenablesthesystemtomeettherequirementofsprayingmediumorlowcostHighVelocityOxy-Fuel(HVOF)coatingsformediumandsmalljobshops.ThedepositedcermetscoatingsbytheDZ9000EsystemhavegoodperformancewithaveragemicrohardnessHV0.2ofmorethan1000andthebondstrengthbetweencoatingandsubstrateofgreaterthan50MPa.

简介：Basedonthemethodofartificialneuralnetwork,anewapproachhasbeendevisedtopredictthemechanicalpropertyofE4303electrode.Theoutlinedpredicationmodelfordeterminingthemechanicalpropertyofelectrodewasbuiltupontheproductiondata.Theresearchleveragesabackpropagationalgorithmastheneuralnetwork'slearningrule.Theresultindicatesthattherearepositivecorrelationsbetweenthepredictedresultsandthepracticalproductiondata.Hence,usingtheneuralnetwork,predicationofelectrodepropertycanberealized.Forthefirsttime,thisresearchprovidesamorescientificmethodfordesigningelectrode.

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简介：Fe3AlandCr18-Ni8steelwerebondedinvacuumandaninterfacewasformedbetweenFe3AlandCr18-Ni8steel.Stressdistributionatthediffusion-bondedinterfacewasresearchedbynumericalsimulationandfiniteelementmethod(FEM).TheresultsindicatedthatthepeakstressappearedattheinterfacenearCr18-Ni8steelside.Thisisthekeyfactortoinducecrackatthisposition.Withtheenhancementofheatingtemperature,thepeakstressatthebondedinterfaceincreases.Whenthetemperatureis1100℃,thepeakstressisupto65.9MPa,whichisbiggerthanthatat1000℃by9.4%.Inaddition,thepeakstressbecomesbiggerwiththeincreaseofthethicknessofbasemetalfrom1mmto8mm.Whilethethicknessismorethan8mm,thepeakstressvariesslightlywiththechangeofthethickness.

简介：瑞士科技创新领跑企业optrelAG，最新推出了一款动力空气净化呼吸器e3000，据了解它能提供最佳的防护和舒适性，保证焊接工作更高效。最高防护级别TH3P，保证最好的安全性。在炯雾、粉尘和气体的外部工作环境下，为了保证焊工的健康，必须配备高效的动力空气净化呼吸器。E3000呼吸器与optrele600专家版焊帽结合使用，町提供符合TH3P的最高级别防护，满足ENl294l指令要求（欧洲标准）。

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简介：ESD(electrosparkdeposition)isapromisingprocesstoproducehardandwear-resistingcoatingsonmetallicsubstrates.InthispapermicrostructureandinterfacialcharacteristicsoftheWC92-Co8coatedontitaniumandcarbonsteelarepresented.Ametallurgicalbondingbetweenthecoatingandsubstrateisobtained.TheTielementwasfoundtodistributeinWC92-Co8atthemetalpool,aswellastheinterfacebydiffusion.SomenewphaseswereproducedinthecoatinglayerduetothechemicalreactionduringtheESDprocess.ExperimentalobservationandthermodynamicanalysiswereutilizedtostudythemechanismofESD.

简介：TiC/Cr18Ni8steelbondedcarbidesweresynthesizedbyvacuumsinteringwithmixedpowdersofiron,ferrotitanium,ferrochromium,colloidalgraphiteandnickelasrawmaterials.Themicrostructureandmicrohardnessofthesteelbondedcarbideswereanalyzedbyscanningelectronmicroscope(SEM),X-raydiffraction(XRD)andRockwellhardometer.ResultsshowthatthephasesofsteelbondedcarbidesmainlyconsistofTiCandFe-Cr-Nisolidsolution.ThesynthesizedTiCparticlesarefine.Mostofthemarenotmorethan1μm.Withtheincreaseofsinteringtemperature,theporosityofTiC/Cr18Ni8steelbondedcarbidesdecreasesandthedensityandhardnessincrease,butthesizeofTiCparticlesslightlyincreases.Underthesamesinteringconditions,thedensityandhardnessofsteelbondedcarbideswithC/Tiatomicratio0.9arehigherthanthosewithC/Tiatomicratio1.0.TheTiCparticleswithC/Tiatomicratio0.9aremuchfinerandmorehomogeneous.

简介：Thefatiguepropertiesoffrictionstirwelded(FSW)buttjointandbasemetalofMB8magnesiumalloywereinvestigated.ThecomparativefatiguetestswerecarriedoutusingEHF-EM200K2-070-1AfatiguetestingmachineforbothFSWbuttjointandbasemetalspecimens.ThefatiguefractureswereobservedandanalyzedusingascanningelectronmicroscopeofJSM-6063LAtype.TheexperimentalresultsshowthatthefatigueperformanceoftheFSWbuttjointofMB8magnesiumalloyissharplydecreased.Theconditionalfatiguelimit(2×10~6)ofbasemetalandweldedbuttjointisabout77.44MPaand49.91MPa,respectively.Theconditionalfatiguelimit(2×10~6)oftheweldedbuttjointis64.45%ofthatofbasemetal.Themainreasonsarethattheweldingcanleadtostressconcentrationintheflasharea,tensileweldingresidualstressintheweldedjoint(Theresidualstressvaluewas30.5MPa),aswellasthegrainsizeisnotuniformintheheat-affectedzone.Thecleavagestepsorquasi-cleavagepatternspresentonthefatiguefracturesurface,thefracturetypeoftheFSWbuttjointbelongstoabrittlefracture.

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简介：中国铁路总公司4月30日召开电话会议，再度调整今年的铁路固定资产投资计划，将今年铁路投资总额上调至8，000亿元人民币．仅次于2010年8426．52亿元的历史顶点。新项目从年初计划的44个飙升至64个，今年新投入运营的线路要确保达到7000公里以上，

简介：<正>由中华全国总工会、科学技术部、人力资源和社会保障部联合举办的第三届全国职工职业技能大赛于圆满地落下帷幕。大赛共设焊工、钳工、维修电工、速录师、数控车工、数控铣工、加工中心操作工、数控机床装调维修工8个工种的比赛,并产生了35名优秀选手、10个团体名次奖和8个优秀组织奖。2009年11月9日

简介：<正>2009年是天津地铁工地上最繁忙的一年,不仅要加快2、3、9号线建设,还将开工5、6号线。今年,天津市要完成2、3号线地铁工程中全部42

简介：ＴｈｅｒｍａｌｂｅｈａｖｉｏｒｏｆＢ４Ｃｐａｒｔｉｃｌｅｓｕｎｄｅｒｐｌａｓｍａａｒｃｐｏｗｄｅｒｓｕｒｆａｃｉｎｇｃｏｎｄｉｔｉｏｎ￥ＷＡＮＧＸｉｂａｏ；ＺＨＡＮＧＷｅｎｙｕｅ；ＬＵＴｏｎｇｌｉａｎｄＰＥＮＧＪｉｅ(ＨｅｂｅｉＵｎｉｖｅｒｓｉｔｙ...

简介：近期，据北京市基础设施投资有限公司（简称京投公司）信息，专门服务于北京市轨道交通建设发展的北京基石基金揭牌，这也是全国首只城市轨道交通装备制造产业专业化投资基金。该基金总体规模15亿元人民币，预计可带动5吲乙元轨道交通相关产品、服务市场份额。基石基金将重点投资于轨道交通装备制造等战略出新兴产业领域，

简介：Anewhardfacingprocess,reactivebrazecoatingprocess(RBCC)wasstudied,and(TiC+Cr3C2)/FecompositecoatingswerepreparedbyRBCCusingcarbon,Cr3C2,iron,ferrochromiumandtitaniumpowderastherawmaterialsinvacuumbrazefurnace.TheresultsshowthatTiCisin-situsynthesizedinthecoatings.ThemethodsofintroducingCr3C2havegreateffectsonthedistributionofTiC.AddingCr3C2directlytotherawmaterialsforcoatings,fineTiCparticlesaggregateintodiscoidsparalleltothecoatingsurface,whereas,in-situsynthesizingCr3C2incoatings,theaggregationsofTiCarelumpish.Duringbrazecoating,Cr3C2particlesdirectlyaddeddissolveandprecipitatetobecomeneedle-shaped.Thecoatingshaveanevenandsmoothsurfaceandarecombinedwiththeirmildsteelsubstratesbyametallurgicalbonding.

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简介：Duetothedisturbancesofspatters,dustsandstrongarclight,itisdifficulttodetectthemoltenpooledgeandtheweldlinelocationinCO2weldingprocesses.Themedianfilteringandself-multiplicationwasemployedtopreprocesstheimageoftheCO2weldinginordertodetecteffectivelytheedgeofmoltenpoolandthelocationofweldline.TheB-splinewaveletalgorithmhasbeeninvestigated,theinfluenceofdifferentscalesandthresholdsontheresultsoftheedgedetectionhavebeencomparedandanalyzed.TheexperimentalresultsshowthatbetterperformancetoextracttheedgeofthemoltenpoolandthelocationofweldlinecanbeobtainedbyusingtheB-splinewavelettransform.Theproposededgedetectionapproachcanbefurtherappliedtothecontrolofmoltendepthandtheseamtracking.

简介：ThediffusionbondingofAZ3\BMgalloyandQ235steelwasinvestigatedwithaZn-5AIalloyasinterlayerandunderdifferentholdingtimerangingfrom3to1200s.Themicrostructureandphasecompositionsofbondedjointswerecharacterizedbyscanningelectronmicroscopy(SEM),energydispersivespectrometer(EDS)andX-raydiffraction(XRD)methods.TheshearstrengthofMgalloy/steeljointswasmeasuredbytensiletester.Itwasfoundthatthemicrostructureofbondedjointsevolveddramaticallyalongwiththeprolongationofholdingtime.Undertheholdingtimeof3s,themainpartofjointwascomposedofMgZn2phaseanddispersedAl-richsolidsolutionparticles.Whenincreasedtheholdingtimemorethan60s,theexcessivesolutionofAZ3\Bintotheinterfacialreactionarealedtotheformationofcoarsephaseandeutecticmicrostructure,andalsothecomplexFe-AlandMg-Al-ZnIMCsattransitionlayerclosedtoQ235steelside.Accordingtothetensiletestingcharacterizations,thejointsobtainedunderholdingtimeof3sexhibitedthebestshearstrengthof84MPa,andthefractureoccurredattheintermediarypartofjointwheretheflexibleAl-richsolidsolutionparticlescouldhelptoimpedethemicrocrackpropagations.Withprolongingtheholdingtimeto600s,theshearstrengthofjointswasdeterioratedenormouslyandthefracturepositionwasshiftedtothetransitionlayerpartclosedtoQ235steel.