简介：Tostudythemechanicalpropertiesofthefilm/substratestructure,thefiniteelementcodeABAQUSv6.9-1isadoptedtosimulatethetensilemechanicalbehaviorofthenanoscalethinfilmbondedtoasubstrate.Thebifurcationphenomenonofthestructureunderuniaxialtensionisfound:thesingle-neckdeformation,themultiple-neckdeformationandtheuniformdeformation.Thesubstrateandthefilmareregardedaspower-hardeningmaterialsobeyingtheJ2deformationtheory.Firstly,theinfluenceofmaterialhardeningmatchontensilebifurcationmodeisanalyzedunderperfectlywell-bondedinterfacecondition.Then,theeffectsofinterfacialstiffnessandothersuperficialdefectssurroundingtheimperfectiononbifurcationmodeareinvestigated.Itisconcludedthatunderthewell-bondedinterfacecondition,ifthestressofthesubstrateislargerthanthefilm,thefilmwilluniformlydeformwiththesubstrate;ifthestressofthesubstrateissmallerthanthefilm,thefilmwillformasingleneck,exceptthecasethataweakly-hardeningfilmisbondedtoasteeply-hardeningsubstratewhenmultipleneckscanbeformed.Withthedecreaseofinterfacialstiffness,theuniformdeformationmodecantransformintothemultiple-neckdeformationmode,andfurthertransformintothesingle-neckdeformationmode.Andotherdefectssurroundingtheimperfectioncaninfluencethewavelengthofdeformationandnecknumber.

简介：AdataacquisitionsystembasedonLabVIEWisdesignedandimplemented,andelectro-discharge(ED)finetruingofmetal-bondedfine-graindiamondwheelbasedonreal-timemonitoringisresearched.Real-timemonitoringnotonlymakesefficientimpulsespecificationofEDtruingeasilyobtained,butalsoisgoodfortimelyidentifyingno-load,avoidingshortcircuitandarcdischargephenomenaandthenforobtainingnormalmachiningstate.EDfinetruingofthefine-grainwheelincludestwosteps:roughtruingforhighefficiencyandfinetruingforhighprecision.FinalEDtruingprecisionandefficiencynotonlydependonelectricprocessspecification,butalsoisconcernedwithelectrodeshape,insulatedperformanceofoperatingfluidandverticalfeedquantityvalueandfrequency.ExperimentsindicatethatEDfinetruingbasedonreal-timemonitoringcanimprovethetruingprecisionandefficiency.AveragemachiningefficiencyofW10wheelisabout0.95μm/min;thefinalrun-outbyEDtruingislessthan2μm.

简介：摘要：传统温压成形过程中由于压力分布不均匀易造成NdFeB粘结磁体各部分密度和强度的不均匀，为提高NdFeB粘结磁体的性能，对温压成形过程中NdFeB粘结磁体进行保压固化。研究表明温压压制粘结NdFeB磁体后，对NdFeB粘结磁体保压固化一段时间，不仅提高磁体的密度和综合磁性能，还可以改善磁体的表面质量。