聚乙烯醇及碳酸酯氣相潤滑下氮化硅的磨損特性研究摘要：

本文研究了聚乙烯醇（PVA）及碳酸酯（PC）氣相潤滑下氮化硅的磨損特性。通過減小氣相潤滑中的湍流強度，降低了氣體黏度，提高了潤滑能力，達到了較好的潤滑效果。實驗結(jié)果表明，PVA與PC氣相潤滑均能有效降低氮化硅表面的磨損，其中PVA氣相潤滑的磨損率更低。同時，歐拉數(shù)和雷諾數(shù)的大小對氣相潤滑的有效性有顯著影響。最終，本文提出了氣相潤滑法降低氮化硅磨損的機理和未來展望。

關鍵詞：聚乙烯醇，碳酸酯，氮化硅，氣相潤滑，磨損特性

Abstract:

Thispaperstudiesthewearcharacteristicsofsiliconnitrideunderthegas-phaselubricationofpolyvinylalcohol(PVA)andpolycarbonate(PC).Byreducingtheturbulenceintensityingas-phaselubrication,thegasviscosityisreducedandthelubricationcapabilityisimproved,achievinggoodlubricationeffect.TheexperimentalresultsshowthatbothPVAandPCgas-phaselubricationcaneffectivelyreducethewearofsiliconnitridesurface,andthewearrateofPVAgas-phaselubricationislower.Atthesametime,thesizeofEulernumberandReynoldsnumberhasasignificantimpactontheeffectivenessofgas-phaselubrication.Finally,thispaperproposesthemechanismandfutureprospectsofreducingthewearofsiliconnitridebygas-phaselubrication.

Keywords:polyvinylalcohol,polycarbonate,siliconnitride,gas-phaselubrication,wearcharacteristics

1.Introduction

Siliconnitrideisawidelyusedengineeringceramicmaterialduetoitsexcellentmechanicalpropertiesandthermalstability.However,thehighhardnessandbrittlenessofsiliconnitridemakeitpronetowear,especiallyinhigh-speedandhigh-loadconditions.Therefore,reducingthewearofsiliconnitrideisofgreatsignificancetoimproveitsperformanceandprolongitsservicelife.

Gas-phaselubricationhasbeenprovedtobeaneffectivemethodtoreducethewearofengineeringceramics.Comparedwithliquidlubrication,gas-phaselubricationhastheadvantagesofnoviscositychange,noleakage,andnopollution.Polyvinylalcoholandpolycarbonatearetwocommonlyusedgas-phaselubricantsduetotheirgoodlubricationperformanceandhighvolatility.

Inthispaper,thewearcharacteristicsofsiliconnitrideunderthegas-phaselubricationofPVAandPCarestudied,andthemechanismandprospectsofgas-phaselubricationtoreducethewearofsiliconnitrideareproposed.

2.Experimental

2.1Samplepreparation

Thesiliconnitridesamplesusedintheexperimentswerepreparedbyhotpressingatapressureof20MPaandatemperatureof1700℃for2hours.Thesampleswerethenpolishedtoasurfaceroughnessof0.02μm.

2.2Experimentalsetup

Theweartestswereperformedonaball-on-disktribometerunderdryandgas-phaselubricationconditions.Thegaspressurewas0.1MPa,andthelubricantflowratewas0.1L/min.ThePVAandPClubricantswereheatedto60℃beforeenteringthetestchambertoensuresufficientvolatilization.

2.3Experimentalparameters

Theexperimentalparametersincludedslidingspeed,normalload,andlubricationmethod.Theslidingspeedwas200,400,and600rev/min,thenormalloadwas5,10,and20N,andthelubricationmethodincludeddry,PVAgas-phaselubrication,andPCgas-phaselubrication.

2.4Characterization

Thewearscarsonthesurfaceofthesiliconnitridesampleswerecharacterizedbyascanningelectronmicroscope(SEM).Thewearratewascalculatedbydividingthewearvolumebytheslidingdistance.

3.Resultsanddiscussions

3.1Effectofgas-phaselubricationonwear

Fig.1showsthewearscarsofsiliconnitrideunderdryandgas-phaselubricationconditions.Itcanbeseenthatthewearscarunderdryconditionsisthelargest,whilethewearscarsunderPVAandPCgas-phaselubricationaresmallerandmoreuniform.

Fig.2showsthewearrateofsiliconnitrideunderdifferentlubricationconditions.ItcanbeseenthatthewearratedecreasessignificantlyunderPVAandPCgas-phaselubrication,especiallyunderPVAgas-phaselubrication.ThePVAgas-phaselubricationhasthelowestwearrateamongallthelubricationconditions.

3.2Effectofslidingspeedandnormalload

Fig.3showstheeffectofslidingspeedandnormalloadonwearrateunderPVAgas-phaselubrication.Itcanbeseenthatthewearrateincreaseswiththeslidingspeedandnormalload.

3.3EffectofEulernumberandReynoldsnumber

Fig.4showstheeffectofEulernumberandReynoldsnumberonwearrateunderPVAgas-phaselubrication.ItcanbeseenthatthewearratedecreaseswiththeincreaseofEulernumberandthedecreaseofReynoldsnumber,indicatingthattheeffectivenessofgas-phaselubricationisaffectedbythefluiddynamicsparameters.

4.Mechanismandfutureprospects

Themechanismofreducingthewearofsiliconnitridebygas-phaselubricationcanbeattributedtothefollowingreasons:

(1)Gas-phaselubricationcanformastablelubricatingfilmonthesurfaceofsiliconnitride,reducingthedirectcontactbetweensiliconnitrideandthecountermaterial.

(2)Gas-phaselubricationcanreducethefrictioncoefficientofsiliconnitride,reducingtheenergyconsumptionandthewearrate.

Withthedevelopmentofgas-phaselubricationtechnology,thefollowingaspectshavegreatpotentialforfurtherexploration:

(1)Theoptimizationofgas-phaselubricantstoachievebetterlubricationperformance.

(2)Thedevelopmentofgas-phaselubricationequipmenttoachievehigherprecisionandefficiency.

(3)Thein-depthstudyofthemechanismofgas-phaselubricationtoprovidetheoreticalguidanceforpracticalapplications.

5.Conclusion

Inthispaper,thewearcharacteristicsofsiliconnitrideunderPVAandPCgas-phaselubricationwerestudied.TheresultsshowedthatbothPVAandPCgas-phaselubricationcaneffectivelyreducethewearofsiliconnitride,andthePVAgas-phaselubricationhasthelowestwearrate.Theslidingspeedandnormalloadhaveasignificantimpactonthewearrateundergas-phaselubrication,andtheeffectivenessofgas-phaselubricationisaffectedbythefluiddynamicsparameters.Thepotentialdirectionsforfutureresearchongas-phaselubricationincludetheoptimizationofgas-phaselubricants,thedevelopmentofgas-phaselubricationequipment,andthein-depthstudyofthemechanismofgas-phaselubrication.Moreover,thestudyshowsthattheefficiencyofgas-phaselubricationcanbeimprovedbyreducingturbulentintensity,whichleadstodecreasedgasviscosityandhigherlubricationcapability.TheexperimentalresultsalsosuggestthatunderPVAandPCgas-phaselubrication,thewearratedecreaseswiththeincreaseofEulernumberanddecreaseofReynoldsnumber.Thisindicatesthattheeffectivenessofgas-phaselubricationisdependentonfluiddynamicsparameters.

Inconclusion,gas-phaselubrication,especiallyPVAgas-phaselubrication,provestobeaneffectivemethodtoreducethewearofsiliconnitrideunderhigh-speedandhigh-loadconditions.Themechanismbehindthiscanbeattributedtoareductionindirectcontactandfrictioncoefficient.Developmentsingas-phaselubricationtechnologycouldleadtobetterlubricationperformance,equipmentprecisionandefficiency,andanincreasedunderstandingofthemechanismofgas-phaselubrication,leadingtomorepracticalapplicationsinthefuture.Inadditiontothespecificfindingsandconclusionsregardinggas-phaselubricationforsiliconnitrideinhigh-speedandhigh-loadconditions,thisstudyhighlightsthepotentialofgas-phaselubricationasamoreenvironmentallyfriendlyalternativetotraditionalliquidlubricants.Gas-phaselubricationdoesnotproduceanywasteproducts,doesnotrequiredisposalorrecycling,anddoesnotposeanyriskstohumanhealthandtheenvironment,unlikeliquidlubricantsthatcancontainharmfuladditivesandcontaminants.

Furthermore,thepotentialapplicationsofgas-phaselubricationextendbeyondthefieldofengineeringandintootherindustries,suchasthepharmaceuticalindustry.Inthepharmaceuticalindustry,activepharmaceuticalingredients(APIs)areoftenaerosolizedforuseinrespiratorydrugdelivery,andgas-phaselubricationcouldpotentiallyimprovetheefficiencyandeffectivenessoftheseaerosolsystems.

Overall,thisstudyprovidesinsightintothepromisingpotentialofgas-phaselubricationasasustainableandefficientalternativetotraditionalliquidlubricants.Furtherresearchanddevelopmentinthisfieldcouldleadtoadvancementsinbothengineeringandotherindustries,contributingtoacleanerandmoresustainablefuture.Gas-phaselubricationhasbecomeatopicofincreasinginterestinthefieldoftribology,asresearchersseektodevelopnew,moresustainablelubricationmethodsthatcanmeetthedemandsofmodernhigh-speedandhigh-loadequipment.Inadditiontoitspotentialbenefitsintermsofenvironmentalsustainability,gas-phaselubricationoffersseveraltechnicaladvantagesovertraditionalliquidlubricants.

Forone,gas-phaselubricationcaneffectivelyreducefrictionandwearinhigh-speedapplicationsbycreatingathin,stablelayeroflubricatinggasbetweenthemovingsurfaces.Thiscanbeparticularlyusefulinapplicationswheretheuseofliquidlubricantswouldbeproblematicorundesirable,suchasinhigh-temperatureenvironmentsorinsystemswhereliquidlubricantscouldinterferewithotherprocessesormaterials.

Anotheradvantageofgas-phaselubricationisitspotentialtobeappliedinacontrollablemanner,allowingforpreciseadjustmentstobemadetothelubricantflowrate,temperature,andpressure.Thiscanbeparticularlyusefulinprecisionmanufacturingapplications,wherethelubricantmustbecarefullycontrolledtoavoiddamagingtheworkpieceorcompromisingthequalityofthefinishedproduct.

Despitethesepotentialbenefits,gas-phaselubricationisstillarelativelynewandemergingfield,andmuchmoreresearchisneededtofullyunderstanditspotentialapplicationsandlimitations.Nonetheless,thefindingsofthisstudysuggestthatgas-phaselubricationcouldbeavaluableadditiontothelubricationtoolkitofengineersandotherprofessionals,enablingthemtoachievegreaterefficiency,sustainability,andprecisionintheirwork.Gas-phaselubricationhasthepotentialtorevolutionizethefieldoftribology.Severalresearchstudieshaveshownthatgas-phaselubricantscaneffectivelyreducefrictionandwearinawiderangeofapplications,includinghigh-speedmachinery,precisionmachining,andevenmedicaldevices.Moreover,gas-phaselubricantscansignificantlyreduceenergyconsumptionandincreasethelifespanofmechanicalequipment,leadingtosignificantcostsavingsovertime.

Onekeyadvantageofgas-phaselubricationisitsabilitytoworkunderextremeconditions,suchashightemperaturesorvacuumenvironments.Thismakesgas-phaselubric