鑄鐵材料在邊界潤(rùn)滑條件下形成薄片狀磨屑的塑性流動(dòng)機(jī)制

鑄鐵材料在邊界潤(rùn)滑條件下形成薄片狀磨屑的塑性流動(dòng)機(jī)制Abstract

Inthisstudy,theformationmechanismofthinsheet-likedebrisincastironunderboundarylubricationconditionswasinvestigatedbasedontheplasticflowmechanism.Theresultsshowedthatthethinsheet-likedebriswasmainlyformedbytheshearingandbreakingofthemicrocrystallinestructureofcastironundertheactionoftangentialforceduringtheslidingprocess.Theformationofthinsheet-likedebriswascloselyrelatedtothecontentanddistributionofgraphiteincastiron.Thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionscanprovideatheoreticalbasisforthedesignandselectionoflubricantsandmaterialstoreducefrictionandwear.

Introduction

Castironmaterialsarewidelyusedinvariousmachineryandequipmentduetotheirexcellentmechanicalpropertiesandgoodcastingperformance.However,undertheactionofexternalloads,thefrictionalheatgeneratedduringtheslidingprocesscancauseseverewearofthecastironsurface,resultingintheformationofdebris.Thecharacteristicsandformationmechanismofdebrishaveagreatimpactontheperformanceandlifeofmechanicalequipment.Therefore,itisofgreattheoreticalandpracticalsignificancetostudytheformationmechanismofdebrisincastironmaterialsunderboundarylubricationconditions.

Theory

Underboundarylubricationconditions,thefrictionalheatgeneratedduringtheslidingprocesscannotbeeffectivelydissipated,resultinginhighsurfacetemperaturesandhighpressureconditions.Asaresult,themechanicalpropertiesofcastironmaterialsaregreatlyreduced,andplasticdeformationandfracturearepronetooccur.Therefore,thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionsisofgreatsignificanceforrevealingtheformationmechanismofdebris.

Method

Inthisstudy,thecastironmaterialwasselectedastheresearchobject.Thetestwascarriedoutonapin-on-diskfrictionandweartesterunderboundarylubricationconditions.Themorphologyandcompositionofthedebrisgeneratedduringtheslidingprocesswereobservedandanalyzedbymeansofscanningelectronmicroscopy(SEM)andenergydispersiveX-rayspectroscopy(EDS).

ResultsandDiscussion

Underboundarylubricationconditions,thegraphiteincastironwillbeexposedtothesurfaceduetothepeelingandspallingofthesurfacelayer.Duringtheslidingprocess,thetangentialforceactingonthesurfaceofthecastironmaterialwillcausethegraphitetorotateandslide,andthemicrocrystallinestructureofthecastironwillbeshearedandbroken,therebyformingthinsheet-likedebris.Theformationmechanismofthinsheet-likedebrisiscloselyrelatedtothecontentanddistributionofgraphiteincastiron.Whenthegraphitecontentishighandthedistributionisuniform,thecastironhasgoodanti-wearpropertiesandislesspronetodebrisformation.However,whenthegraphitecontentislowandthedistributionisuneven,thecastironispronetoplasticdeformationandfracture,resultingintheformationofalargeamountofdebris.

Conclusion

Thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionscanprovideatheoreticalbasisforthedesignandselectionoflubricantsandmaterialstoreducefrictionandwear.Theresultsofthisstudyshowedthatthethinsheet-likedebrisincastironunderboundarylubricationconditionswasmainlyformedbytheshearingandbreakingofthemicrocrystallinestructureofcastironundertheactionoftangentialforceduringtheslidingprocess.Theformationofthinsheet-likedebriswascloselyrelatedtothecontentanddistributionofgraphiteincastiron.Moreover,itwasfoundthroughthestudythatthesizeandshapeofthethinsheet-likedebrisareinfluencedbytheslidingspeedandload,whichaffectthedegreeofplasticdeformationandfractureofthecastironmaterial.Withanincreaseinslidingspeedandload,theamountandsizeofthedebrisalsoincrease.

Theformationofthinsheet-likedebrisincastironunderboundarylubricationconditionsalsohasanimpactonthewearofthematerial.Thepresenceofdebrisonthesurfaceofthematerialcanleadtoabrasivewear,whichcanfurtheracceleratethewearofthematerial.Therefore,itisessentialtounderstandtheformationmechanismofdebrisandtakemeasurestopreventtheformationandaccumulationofdebris.

Oneeffectivewaytopreventtheformationofdebrisincastironunderboundarylubricationconditionsistouselubricantsthathavegoodboundarylubricationproperties.Theselubricantscanreducethetangentialforceactingonthesurfaceofthematerial,therebyreducingtheshearingandbreakingofthemicrocrystallinestructureandtheformationofdebris.

Inconclusion,thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionscanprovideadeepunderstandingoftheformationmechanismofdebrisanditsimpactonthewearofthematerial.Theresultsofthisstudyhighlighttheimportanceofselectingappropriatelubricantsandtheneedtooptimizethecontentanddistributionofgraphiteincastironmaterialstominimizetheformationofdebrisandprolongtheservicelifeofmachineryandequipment.Asidefromselectingappropriatelubricantsandoptimizingthecontentanddistributionofgraphite,thereareothereffectivewaystopreventtheformationofdebrisincastironunderboundarylubricationconditions.Onewayistoimprovethesurfacefinishofthematerialbyusingfinergrindingmediaoraddingpolishingprocesses.Thesmootherthesurface,thelesslikelydebriswillformandaccumulate.Anotherwayistoincreasethehardnessandstrengthofthematerialbyaddingalloyingelements,heattreatment,orsurfacemodificationtechniques.Aharderandstrongermaterialislesssusceptibletoplasticdeformationandfracture,whichreducestheamountandsizeofdebrisgeneratedduringsliding.

Furthermore,thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionscanalsoprovideinsightsintothedesignandoptimizationofmachineryandequipment.Byunderstandingthefactorsthataffecttheformationofdebris,engineerscanadjusttheparametersofslidingandlubricationtoenhancetheperformanceandreliabilityoftheequipment.Forexample,theycanreducetheslidingspeedandload,increasethelubricationfilmthickness,orusecoatingsorsurfacetreatmentsthatimprovethewearresistanceandreducethefrictioncoefficient.

Insummary,thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionsiscrucialforimprovingthewearresistanceandreducingthedebrisformationinmachineryandequipment.Byapplyingtheinsightsgainedfromthisstudy,manufacturersandusersofcastironmaterialscanprolongtheservicelifeoftheirproducts,reducemaintenancecosts,andenhancetheenergyefficiencyandsustainabilityoftheiroperations.Anothereffectivewaytopreventdebrisformationincastironunderboundarylubricationconditionsistouseadditivesinlubricants.Theseadditivescanimprovetheanti-wearandanti-frictionpropertiesoflubricants,whichreducestheformationandaccumulationofdebrisduringsliding.Somecommonadditivesusedinlubricantsforboundarylubricationapplicationsincludeextremepressure(EP)agents,anti-wear(AW)agents,frictionmodifiers,andanti-oxidants.

EPagentsworkbyformingaprotectivelayeronthesurfaceofthemetal,whichreducesthefrictionandpreventsmetal-to-metalcontact.AWagents,ontheotherhand,provideasacrificiallayerthatabsorbstheweardebrisandprotectsthemetalfromfurtherdamage.Frictionmodifiersreducethefrictioncoefficientandimprovetheslidingperformanceoflubricants,whileanti-oxidantspreventthedegradationoflubricantsandtheformationofharmfulby-products.

Apartfromthesemethods,thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionscanalsoleadtothedevelopmentofnewlubricantsandsurfacecoatings.Forexample,scientistscanusemoleculardynamicssimulationsandothercomputationaltoolstodesignlubricantsandcoatingsthathavetailoredpropertiesandcanwithstandtheextremeconditionsofboundarylubrication.

Inconclusion,thestudyoftheplasticflowmechanismofcastironunderboundarylubricationconditionsisaninterdisciplinaryfieldthatinvolves