碳化硼-碳化硼摩擦副的摩擦磨損特性研究

碳化硼-碳化硼摩擦副的摩擦磨損特性研究摘要：

碳化硼（B4C）和碳化硼（SiC）材料被廣泛應(yīng)用于高溫和高壓條件下的重載應(yīng)用中，優(yōu)異的機(jī)械和熱特性使其成為理想的材料選擇。本文通過系統(tǒng)研究B4C-SiC摩擦副的摩擦磨損特性，探討了材料的結(jié)構(gòu)和組分對摩擦性能的影響。實驗結(jié)果表明，在不同的負(fù)載和速度下，B4C-SiC摩擦副的磨損機(jī)制存在明顯的轉(zhuǎn)變，其磨損過程包括壓碎、拔斷、拉出和剝落等。同時，材料的微觀結(jié)構(gòu)和組分對摩擦磨損性能有著顯著的影響，具有SiC和B4C復(fù)合結(jié)構(gòu)的材料表現(xiàn)出更高的摩擦系數(shù)和更長的磨損壽命。

關(guān)鍵詞：碳化硼；碳化硼；摩擦磨損；材料結(jié)構(gòu)；微觀組織

Abstract:

Boroncarbide(B4C)andsiliconcarbide(SiC)materialsarewidelyusedinheavy-dutyapplicationsunderhightemperatureandpressureconditionsduetotheirexcellentmechanicalandthermalproperties.Inthisstudy,thefrictionandwearcharacteristicsofB4C-SiCfrictionpairsweresystematicallyinvestigatedtoexploretheeffectofmaterialstructureandcompositiononfrictionperformance.TheexperimentalresultsshowthatthewearmechanismofB4C-SiCfrictionpairsundergoessignificanttransitionsunderdifferentloadsandspeeds,includingcrushing,pulling,extraction,andpeeling.Meanwhile,themicrostructureandcompositionofthematerialshaveasignificantimpactonfrictionandwearperformance.MaterialswithacompositestructureofSiCandB4Cexhibithigherfrictioncoefficientsandlongerwearlifetimes.

Keywords:Boroncarbide;Siliconcarbide;Frictionandwear;Materialstructure;Microstructure

Introduction：

Borocarbides(B4C)andsiliconcarbide(SiC)materialshavereceivedwidespreadattentionduetotheirexcellentmechanicalandthermalproperties,suchashighhardness,hightemperatureresistance,goodoxidationresistance,andwearresistance.Thesematerialshavebeenwidelyusedinvariousfieldssuchasaerospace,defense,andnuclearpower.TheuseofB4C-SiCcompositematerialshasalsobeenextendedtothefieldoffrictionmaterials.

TheB4C-SiCfrictionpairprovidesanattractiveopportunitytoeffectivelydecreasefrictionalheatandwear,ensuringreliableoperationwithminimalsystemdamage.Thus,itisessentialtoinvestigatethefrictionandwearcharacteristicsoftheB4C-SiCfrictionpairtooptimizetheirperformanceandusagelife.

Inthisstudy,thefrictionandwearcharacteristicsoftheB4C-SiCpairwereinvestigatedsystematicallytoexploretheirfrictionandwearmechanismsandeffectsofstructureandcompositiononwearperformance.

Experimentalprocedure：

TheB4C-SiCfrictionpairswerepreparedbyhot-pressingB4CandSiCpowders.Thefrictiontestswereconductedunderdryslidingconditionsusingapin-on-disctribometeratroomtemperature.Aloadrangeof2-20Nandaslidingspeedrangeof0.1-1m/swereapplied.

Themicrostructureandcompositionofthematerialswerecharacterizedusingscanningelectronmicroscopy(SEM)andenergy-dispersivespectrometry(EDS).ThewearmechanismandmorphologyofthewornsurfaceswereanalyzedusingSEM.

Resultsanddiscussion：

Effectofload：

TheeffectsofappliedloadonthefrictioncoefficientandwearrateoftheB4C-SiCpairarepresentedinFig.1.Thefrictioncoefficientinitiallyriseswithincreasingloadbeforereachingamaximumvalueataround5N,thendecreasesslightlywithfurtherincreaseinload.Thewearrategraduallyincreasesastheappliedloadincreases.

Atlowload,theabrasivewearmechanismisthedominantone,wheretheSiCparticlesproducemicro-cutsonthewornsurfaceoftheB4C-SiCfrictionpairs.Astheloadincreases,theadhesivewearmechanismoccurs,whereB4CparticlesplasticallydeformandadheretotheSiCsurface,forminganadhesionlayer.Meanwhile,athighloads,thedelaminationwearmechanismisobserved,wherethecompressionstressallowstheSiCparticlestoembedintotheB4Csurface,causingcrackingandspallingoftheB4Cmaterial.

Effectofslidingspeed：

TheeffectsofslidingspeedonthefrictioncoefficientandwearrateoftheB4C-SiCpairsarepresentedinFig.2.Withtheincreaseofslidingspeedfrom0.1to1m/s,thefrictioncoefficientandwearrateincreaseaswell.

Atlowspeed,theabrasivewearmechanismdominateswheretheSiCgrainsremovethewornsurfaceofB4Cthroughmaterialpulverization.Athighspeeds,theadhesionwearmechanismdominates,whereintensefrictionalheatcausesthemeltingandsofteningofB4Cinthecontactregion,leadingtoadhesionandtransferofmaterialbetweentherubbingsurfaces.

Effectofstructureandcomposition：

ThemicrostructureandcompositionoftheB4C-SiCmaterialshavesignificanteffectsontheirfrictionandwearperformance.

MaterialswithacompositestructureofSiCandB4Cshowhighhardness,excellentwearresistance,andhighfrictioncoefficients.TheuniformdistributionofB4CandSiCparticlesimprovesthetribologicalpropertiesofthematerial.

Conclusion：

TheB4C-SiCfrictionpairexhibitscomplexfrictionandwearbehaviorunderdifferentconditions.Themainwearmechanismsincludeabrasivewear,adhesivewear,anddelaminationwear,andthesemechanismsvarywiththeappliedloadandslidingspeed.

Themicrostructureandcompositionofthematerialssignificantlyaffecttheirfrictionandwearperformance.MaterialswithacompositestructureofSiCandB4Cshowhigherfrictioncoefficientsandlongerwearlife.Thesefindingsprovideguidanceforthedesignanddevelopmentofhigh-performanceB4C-SiCcompositematerialsfortribologicalapplications.Furthermore,theresultsofthisstudyprovideinsightsintotheoptimizationofB4C-SiCmaterialsforspecifictribologicalapplications.Forexample,iftheintendedapplicationinvolveshighloads,materialswithahigherB4CcontentmaybepreferabletothosewithahigherSiCcontent.Ontheotherhand,forapplicationsinvolvinghighslidingspeeds,acompositematerialwithanoptimizeddistributionofB4CandSiCparticleswouldbemoresuitable.

Inaddition,thewearbehavioroftheB4C-SiCfrictionpairindicatesthatthematerialcanwithstandhightemperatureandpressureconditionswithoutsignificantfailure.Hence,itcouldbeapotentialcandidateforuseinhigh-temperatureandhigh-pressureapplications,suchasintheaerospaceandnuclearpowerindustries.

Insummary,thisstudyprovidesacomprehensiveunderstandingofthefrictionandwearbehaviorofB4C-SiCcompositematerialsandtheirpotentialusageintribologicalapplications.Thefindingsprovidevaluableinsightintothedesignanddevelopmentofhigh-performanceB4C-SiCmaterialsandcontributetotheadvancementoftribologicalscienceandtechnology.Moreover,theinvestigationofthemechanicalpropertiesofB4C-SiCcompositesfurtheraidsintheoptimizationofthematerialfortribologicalapplications.Thesecompositesexhibitexcellentmechanicalpropertiessuchashighhardness,highelasticmodulus,andexcellentthermalstability.Hence,theypossessgoodwearresistanceandpotentialforapplicationsinvolvinghighloadandslidingconditions.

AnotheradvantageofB4C-SiCcompositesistheirabilitytooperateinharshworkingenvironments,suchasthoseinvolvinghightemperaturesandaggressivemedia.Thesematerialsaresuperioratwithstandinghigh-temperatureoxidationandcorrosion,providingexceptionalresistanceagainstchemicalattack,andpossessinghighthermalshockresistance.

Additionally,theuseofB4C-SiCcompositesprovidesthepotentialforenvironmentalbenefits,specificallyinapplicationsinvolvingenergysavings.Thelowerfrictioncoefficientandimprovedwearresistancecancontributetothereductionofenergylossandmaterialwastage,respectively,leadingtoenergysavingsandenvironmentalprotection.

Inconclusion,B4C-SiCcompositeshavedemonstratedexceptionaltribologicalproperties,makingthemapromisingmaterialforvarioustribologicalapplications.TheoptimizeddesignanddevelopmentofB4C-SiCcompositescouldleadtothecreationofhigh-performancematerialsthatcanoperateunderharshenvironmentalconditions,providingsignificantbenefitstovariousindustries.FurtherstudiesonthetribologicalperformanceofB4C-SiCcompositesareessentialinadvancingmaterialscienceandcreatingnewpossibilitiesfortribologicalapplications.Furthermore,researchershaveinvestigatedtheeffectofdifferentfabricationmethodsonthemechanicalpropertiesandtribologicalbehaviorofB4C-SiCcomposites.OnestudyshowedthattheadditionofasmallamountofSiCparticlesinB4C-SiCcompositescansignificantlyimprovethemechanicalproperties,suchashardness,fracturetoughness,andwearresistance.Anotherstudystatedthattheuseofsparkplasmasintering(SPS)methodcanenhancethemechanicalpropertiesofB4C-SiCcompositesduetotheformationofadensemicrostructurewithareducedamountofporosity.

Moreover,thedevelopmentofnovelsurfacetreatmentsforB4C-SiCcompositescanfurtherenhancetheirtribologicalproperties.Forexample,researchershaveinvestigatedtheeffectoflasersurfacetreatmentonthewearbehaviorofB4C-SiCcomposites.Theresultsshowedthatlaser-treatedB4C-SiCcompositesexhibitsignificantlyreducedwearratesandimprovedwearresistancecomparedtountreatedsamples.

TheapplicationofB4C-SiCcompositesintheaerospaceindustryisanotherareaofinterestduetotheirexceptionaltribologicalpropertiesunderhighloadandslidingconditions.Inaircraftengines,thesematerialscanbeutilizedinbearings,seals,andothercritical