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1.
1 INTRODUCTIONBerylliumhasitsowncharacteristics:lowdensi ty,highmeltingpoint ,highelasticmodulus ,espe ciallyhighspecificstiffness (modulus/density) ,gooddimensionalstability ,etc .Soitisagoodmaterialforinertialguidancesystemandopticalsystem[1~ 3 ] .Powdermetallu…  相似文献   

2.
1 INTRODUCTIONHypereutecticAlSialloyisusedextensivelyaspistonmaterialsduetoitslowcoefficientofthermalexpansionandhighthermalstability.ThekeyfactorwhichinfluencesthepropertiesofhypereutecticAlSialloysisthecoarseprimarysiliconphase,andmuchresearchworkha…  相似文献   

3.
Refinement and thermal analysis of hypereutectic Al-25%Si alloy   总被引:1,自引:0,他引:1  
1 INTRODUCTIONThehypereutecticAl Sialloysexhibitahighlydesirablecombined properties ,suchascastability ,highstrength to weightratio ,lowthermalexpansioncoefficient,highcorrosionandabrasionresistances .SothehypereutecticAl Sialloyshavewidespreadus ageinautomo…  相似文献   

4.
1 INTRODUCTIONTibasedIrO2 coatinganodeswerewildlyusedinelectrochemicalindustryfortheirhighelectrocatalyticactivityandstability[1] .Inanextremecondition ,suchashigh speedelectrodeposition ,however ,thestabilityofIrO2 isnolongersatisfied .Therefore ,themodificat…  相似文献   

5.
Effect of La_2O_3 nanoparticles on properties of molybdenum powder   总被引:1,自引:0,他引:1  
1 INTRODUCTIONAsoneofthealternativesofThO2 Wcathode ,La2 O3 Mothermioniccathode (La Mo)appearedinrecent 30 years[1~ 4 ] .Althoughthiscathodehasgoodemissivity ,ithasnotbeenusedcommerciallybecauseofitspooremissionstability[5~ 8] .Themicrostructurestudyonthiscathodesho…  相似文献   

6.
Eigen elastic mechanics and its variation principle   总被引:3,自引:0,他引:3  
1 INTRODUCTIONTheconceptionofeigenelasticmechanicsbenefitsfromthestandardspacetheory[1~ 4] .Aseriesofstud ies[5~ 7] madebyauthorrecently ,haveestablishedtheeigenformofelasticmechanicsundermechanicalrepre sentationanditsoperationalizedprinciple,butthecorrespon…  相似文献   

7.
Relationship between solid fraction and distribution of Pb in Al-Pb ingot   总被引:4,自引:0,他引:4  
INTRODUCTIONAl Pbhypermonotecticalloyisanewtypebear ingmaterial[1] .Greatemphasishasbeenputonites peciallysince 1990s[2~ 4 ] .PbhasexcellentlubricatingpropertywhichcanmatchthatofSn ,butitscostismuchlowerthanthatofSn ,soAl SnalloyisreplacedbyAl Pballoyinthefieldo…  相似文献   

8.
1 INTRODUCTIONRockisahighlynonlinearmedium ,whosebe haviorcanbecategorizedintoaninitiallinearresponsefollowedbyplasticortheweakenedphaseafterat tainingthepeakstress[1 ] .Traditionally ,theaveragemodulusofrockistakenas 50 %ofelasticmodulusofthepeakstressintrad…  相似文献   

9.
1 INTRODUCTIONMetal plasticdeformationresistanceisoneofthebasicparameterofrollingprocessandequipmentpa rameter[1,2 ] .Theeffectofthedeformationconditionsondeformationresistanceisdifficulttocountandana lyzebymeansoftheoreticalmethodbecausethemetalplasticflo…  相似文献   

10.
Ordered molecular layer structure of lubricating oil adsorbed films   总被引:2,自引:0,他引:2  
1 INTRODUCTIONBoundarylubricationandthin filmlubricationaretwolubricatingstateswidelyexistinginmetalplasticworkingprocess .In 1919Hardyetal[1] firstadvancedtheconceptofboundarylubrication ,in192 9Tomlinson[2 ] disclosedtheintermoleculareffectofboundarylubricatio…  相似文献   

11.
1 INTRODUCTIONTibasedhydrogenstoragealloysbecameattractivebecauseoftheirlargehydrogencapacities.Bernaueretal[1]andLietal[2]pointedoutthatmultielementTibasedhydrogenstoragealloysaremorepromisingmaterialsforpracticalapplications.(TiZr)(MnCrVFe)2alloyisacommon…  相似文献   

12.
Thermal debinding dynamics of novel binder system   总被引:2,自引:0,他引:2  
1 INTRODUCTIONBinderplaysafoundationalpartofincreasingflowandkeepingshapesinthe plasticizing powderextrusionmolding processes[1] .Now ,newbindersystems[2~ 9] aredesignedwithmutli componentsoastochangetherheologicalpropertiesandthermalde bindingbehaviorsofbind…  相似文献   

13.
Crystal structure and thermal stability of martensite in Cu-24Al-3Mn alloy   总被引:2,自引:0,他引:2  
1 INTRODUCTIONCu basedshapememoryalloys (SMA )werestudiedbymanyauthorsinrecentyears[1~ 13 ] .Itisconvincedthattheshapememoryeffectisass  相似文献   

14.
Influence of process parameters on hybrid forming of aluminum sheet   总被引:1,自引:1,他引:0  
1 INTRODUCTIONHybridformingisanewmethodformanufactur ingofmetalsheetandplasticcombinedmacro com positecomponents[1] .Twometalsheetswith pre treatedsurfacesareheldtogetheralongtheiredgesbyclampingoperationofthemoldforhybridformingthroughtheinjectionmachine …  相似文献   

15.
Crystalline structure and morphology of X phase in Cu-Al-Ni-Mn-Ti alloy   总被引:1,自引:0,他引:1  
1 INTRODUCTIONCopperbaseshapememoryalloyshavelowcostsand goodshapememoryproperties .Theirshapememoryeffectsoriginatefromthermo elasticmarten sitictransformations .Alotofworkhasbeendoneonthemartensitictransformations[1,2 ] ,martensiticstructures[3~ 5] ,ageingeff…  相似文献   

16.
1 INTRODUCTIONWiththedevelopmentofcomputertechnologyandartificialintelligence ,newmethodshavebeenap pliedtoimprovecastingproduction[1] .Expertsystemisanimportantbranchofartificialintelligence ,itisessentiallyancomputer programwith“intelligent”characteristi…  相似文献   

17.
1 INTRODUCTIONTiCiswidelyusedasinsitureinforcingparticleinmetalmatrixcomposites[1~ 5] ,becauseithasnotonlyhighmelting point ,hardness,elasticmodulusandexcellentcorrosionresistance,butalsomoreneg ativestandardGibbsformationfreeenergy .Inrecentstudies[6~ 9] ,howe…  相似文献   

18.
1 INTRODUCTIONAcontinuousrecoveryandrecrystallizationmechanism[1,2 ] wasproposedbyLinandcoworkersforthesuperplasticityinlarge graine  相似文献   

19.
1 INTRODUCTIONDiesplayanimportantroleinmodernmanufac turingindustry .Newprocessingtechniques[1] arebe inginnovateddayandday ,suchassparkerosion ,ul trasonicandelectron beammachining ,superplasticformingandsoon .Theirapplicationhasremarkablyimprovedtheefficien…  相似文献   

20.
1 INTRODUCTIONFunctionallygradedmaterials(FGM )isanewkindofnon homogeneouscomposites[1] .Widespreadattentionhasbeenpaidtosuchkindofmaterialsforitssuperiorcharacteristicsandnoveldesignideasandimportantapplicationbackground .Itiswellknownthatformationprocess…  相似文献   

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