1 .Introduction Thezinc -alluminiumalloyhasagoodmechanicsproperty ,anantifrictionandawearingresis tance.Itcanbeusedunderthecertainworkingcondi tionandisadesiredsubstitutematerialoftinbro nzebecauseitsrawmaterialischeaper.InordertoreducethecostanddecreasethematerialquantityofalloyZAS3 5,themanufactureofbimetalcompositeisaneweffectivemethodwhenthepartialal loyZAS3 5issubstitutedbytakingthecheapcarbonsteelasabase. Thelasermoireinterferometryisanon -contactaccuratelyopticaltesttechnologywithahigh -testaccuracy .Thedisplacementfieldoftestsamplecanbeobtaineddirectly .Ithasadvantagesofasmallmeasuringerror,agoodfringequalityandareal-timeobservation .Aninterferometricfringepatternoflargerrange nearthecrackshasbeenobtainedafterthetestsam pleofinterfaceofbimetalcompositeofzincalloyZAS35/carbonsteelismeasuredinthedisplacementfieldunderthethree -pointbendingloadwiththelasermoireinterferom etry.ThephasecompositionofelementofinterfaceofzincalloyZAS35/carbonsteelcanbedefinedwiththeelectronicsc anningmirrormethodandtheXrayphotography.Ami croscopicdisplaywillbedonebetweencrystalwhiskerfiberofbimetalcompositeandbaseandbetweensandwichofeachphasemedium .Thedistributioncompositionofelementofinterf acewillbemeasuredandanalyzedinnumericalquantities,thusthebondinglawofzincalloyZAS35/carbonsteelwillbeapproached .Atheoreticalfoundationwillbelaidforthebette rapplicationofbimetalcompositeofzincalloyZAS35/carbonsteel.2 .MoireInterferometryandExperimentalTechnolog yWhentwobunchesofcoherentplanelightwavesAandBinangleθ=arcsin(λf)areincidentuponthegratingoftestsamplesymmetri cally ,thepositiveandnegative (+and -)firstclassdiffractedlightwillmarchforwardalongthenormaldirectionofthegratingoftestsample.fintheformulaexpressesthefrequencyofgratingoftestsampleandλintheformularepre sentsthewavelengthofincidentlight.Ifα(x .y)andβ(x .y)expressthetwobunchesoflightsAandBrespectively,Fig .1 OpticalPathDiagramviatheMoireInterferomet ryofSymmetricalIncidenceofDouble-beam a=exp
and b=exp(1 )canbewrittenforthecomplexamplitudeoftwobunc hesoflightsAandBbecausethegratingoftestsamp lecausesthephasechangewiththedistortionoftestsample(inordertocalculatethemsimply,theinfluenceofcomplexamplitudevaluewillnotb ecountedintheanalysisofcoherentlightofthispaper) . Thetwobunchesoflightswillinterfereineachotherandforminterferencefringes.Thelightintensitydistributingonthegratingsurfaceoftestsampleis I=(a+b) (a+b) =4cos2 <φab(x ,y) / 2 >.(2 )Inwhich ,φab(x ,y) =φa(x ,y) -φb(x,y) , expressesacomplexconjugation . Assumethedisplacementsoftestsampleinthexandzdirectionsareuandwrespectively . φa(x,y) =2 π/ λ ;φb(x ,y) =<-usinθ+w(1 +cosθ) >2 π/λ;φab(x ,y) =4πusinθ/λ (3 ) Takingtheformula (3 )intotheformula (2 )equals: I=4cos2 (2πusinθ/λ) ;Order:2πusinθ/λ =Nxπ ,Equals : u(x ,y) =Nx/ 2f (4) Nxintheformulaisnumberoffringesforthedisplacementfieldu .Theformula(4)isanexpres sionofufielddisplacement.3 .ExperimentandResults 3 .1ManufactureofTestSample Themanufacturinge ngineeringflowofbimetalcompositeofzincalloyZAS35/carbonsteelisshownasFig .2 .Acrack 5mm (L)and 0 .0 1mm (W )willbecutontheinterfacejointbetweensteelbac kandalloycastingwithalinearcuttingmachine.T hetestsamplewillbefirstburnishedwithametall ographicemerypaperbeforethegratingismadeonthesurfaceoftestsample;then ,itwillbepolishedfinelywithapolishingagentandgroundwiththeemerygypsum .Thesurfaceoftestsamplewillbedegreasedandmadeanimmersioncleaning ,then ,itwillbecleanedwithahotwaterbeforethegratingismade.ThesizeoftestsampleisshownasFig.3.Fig.2 ManufactureEngineeringFlowofBimetalCompositeFig .3 TestSampleforExperimentU -Field V -FieldFig.4. MoireInterferometricFringePattern (U -fieldandV -fieldDisplacement) 3 .2Grating-making Ahologramphasegrating(6(wi llbemadeonthesurfaceoftestsamplewithagrating-makingprocessofphasetransfermethod .Thegrating-makingdensityis 1 2 0 0L/mm . 3 .3ExperimentalProcessandResultsForatestdevice,averticalthree -pointbendingstressapplicationframeisu