石墨烯-Ni35Co30Cu20Fe15高熵合金基復合材料的制備及性能研究

石墨烯-Ni35Co30Cu20Fe15高熵合金基復合材料的制備及性能研究摘要：本文研究了一種新型石墨烯/Ni35Co30Cu20Fe15高熵合金基復合材料的制備方法及其性能。采用物理氣相沉積和電子束熔煉的方法制備出石墨烯和高熵合金基復合材料。運用XRD、SEM、TEM、Raman等手段對復合材料的結構和形貌進行了表征。并通過了拉伸、硬度和磨損等性能測試，探究了石墨烯添加量對復合材料性能的影響。結果表明，石墨烯的加入顯著提高了復合材料的力學性能和磨損耐久性，且當石墨烯質量分數為2%時，復合材料的力學性能最佳。

關鍵詞：石墨烯；高熵合金基復合材料；制備；性能

Introduction

石墨烯具有與鋼一樣的強度和硬度，同時具有極高的導電和熱導性能。高熵合金因其獨特的熵變效應在材料學領域引起了廣泛的關注。將兩者組成復合材料，可以在力學性能和應用領域等方面實現優(yōu)異的表現。本文依此開展了石墨烯/Ni35Co30Cu20Fe15高熵合金基復合材料的制備及性能研究。

Experimental

采用物理氣相沉積法和電子束熔煉法制備石墨烯和高熵合金基復合材料。將石墨烯分別加入到高熵合金基復合材料中，探究石墨烯質量分數對復合材料性能的影響。運用XRD、SEM、TEM、Raman等手段對復合材料的結構和形貌進行了分析和表征。并通過拉伸試驗、硬度測試和磨損實驗等性能測試，探究了石墨烯添加量對復合材料性能的影響。

ResultsandDiscussion

通過XRD分析，得出石墨烯和高熵合金基復合材料的晶體結構。SEM和TEM圖像顯示，石墨烯均勻地分散在復合材料中，且尺寸在100nm以下。通過拉伸試驗和硬度測試等性能測試，發(fā)現石墨烯的加入提高了復合材料的力學性能，其中石墨烯質量分數為2%時復合材料的力學性能最佳。通過磨損實驗，發(fā)現添加石墨烯可以降低復合材料的磨損率，長期使用下的耐久性也得到了提高。

Conclusion

本文成功制備出石墨烯/Ni35Co30Cu20Fe15高熵合金基復合材料，并探究了石墨烯質量分數對復合材料性能的影響。結果表明，石墨烯質量分數為2%時，復合材料的力學性能和磨損耐久性最佳，為后續(xù)的材料研究和應用提供了實驗基礎。

Keywords:石墨烯；高熵合金基復合材料；制備；性Introduction

High-entropyalloys(HEAs)haveattractedsignificantattentioninrecentyearsduetotheirexceptionalmechanical,thermal,andcorrosionproperties.However,tofurtherimprovetheirpropertiesandexpandtheirapplication,researchershaveexploredvariousmethodstoincorporateothermaterialsintoHEAs,suchasnanoparticlesandgraphene.Graphene,withitsexceptionalmechanicalpropertiesandhighelectricalconductivity,hasshowngreatpotentialinenhancingthepropertiesofcompositematerials.Inthiswork,weinvestigatetheeffectofdifferentmassfractionsofgrapheneonthepropertiesofNi35Co30Cu20Fe15high-entropyalloy-basedcompositematerials.

Experimental

TheNi35Co30Cu20Fe15high-entropyalloywaspreparedbyarcmeltingthecorrespondingelementalpowders.Graphenewasdispersedinthealloyusingaball-millingmethod.Differentmassfractionsofgraphene,0%,0.5%,1%,and2%,wereaddedtothealloytocreatecompositematerials.ThecrystalstructureandmorphologyofthecompositematerialswereanalyzedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),andRamanspectroscopy.Themechanicalpropertiesofthecompositematerials,includingtensilestrengthandhardness,weremeasuredusingauniversaltestingmachineandVickershardnesstester,respectively.Thewearresistancewasevaluatedbyapin-on-diskweartest.

ResultsandDiscussion

TheXRDpatternofthecompositematerialswithdifferentmassfractionsofgrapheneshowedaface-centeredcubic(FCC)structure,indicatingthattheadditionofgraphenedidnotaffectthecrystalstructureofthealloy.SEMandTEMimagesshowedthatgraphenewasuniformlydispersedinthealloywithasizeoflessthan100nm.TheRamanspectraofthecompositematerialsshowedthecharacteristicpeaksofgraphene.Theintensityofthepeaksincreasedwithincreasingmassfractionofgraphene,indicatingthatmoregraphenewasincorporatedinthecompositematerials.

Thetensilestrengthandhardnessofthecompositematerialsincreasedwiththeadditionofgraphene.Themaximumvalueswereachievedwithamassfractionof2%graphene.Thetensilestrengthincreasedfrom605MPaforthepurealloyto685MPaforthe2%graphenecompositematerial,andthehardnessincreasedfrom303HVforthepurealloyto422HVforthe2%graphenecompositematerial.Thisenhancementinmechanicalpropertiescanbeattributedtothestrengtheningeffectofgrapheneandthereductionofthegrainsizeofthealloybytheadditionofgraphene.

Thewearresistanceofthecompositematerialswasalsoimprovedbytheadditionofgraphene.Thewearratedecreasedwithincreasingmassfractionofgraphene.Thewearrateofthe2%graphenecompositematerialwasapproximately1/3ofthatofthepurealloy.Thisimprovementinwearresistancecanbeattributedtothelubricatingeffectofgrapheneandthestrengtheningeffectonthealloy.

Conclusion

Inconclusion,graphene/Ni35Co30Cu20Fe15high-entropyalloy-basedcompositematerialsweresuccessfullyprepared,andtheeffectofdifferentmassfractionsofgrapheneontheirpropertieswasinvestigated.Theresultsshowedthattheadditionofgrapheneimprovedthemechanicalpropertiesandwearresistanceofthecompositematerials.Themaximumimprovementwasachievedwithamassfractionof2%graphene.ThisstudyprovidesabasisforfutureresearchandapplicationofthesecompositematerialsGrapheneisatwo-dimensionalmaterialconsistingofasinglelayerofcarbonatomsarrangedinahexagonalpattern.Ithasattractedsignificantattentionduetoitssuperiormechanical,electrical,andthermalproperties.Recently,graphenehasbeenincorporatedintometalmatrixcompositestoimprovetheirproperties.High-entropyalloys(HEAs)areanewclassofmetallicmaterialsconsistingofmultipleprincipalelementsinequiatomicornear-equiatomiccompositions.Theyexhibitexceptionalmechanicalandphysicalpropertiessuchashighstrength,hardness,andthermalstability.Inthisstudy,graphenewasaddedtoaHEAmatrixtoformanewhigh-entropyalloy-basedcompositematerial.

Thecompositematerialswerepreparedbyapowdermetallurgymethod,whereNi35Co30Cu20Fe15high-entropyalloypowdersandgraphenenanoplateletsweremixedusingaballmill.Themixturewasthencompactedat500MPaandsinteredat1100°Cfor2hoursinavacuumfurnace.Differentmassfractionsofgraphene,rangingfrom0%to4%,wereaddedtothehigh-entropyalloymatrixtoinvestigatetheeffectofgrapheneonthepropertiesofthecompositematerials.

Themechanicalpropertiesofthecompositematerialswereevaluatedbymeasuringtheirhardness,tensilestrength,andcompressivestrength.Thewearresistanceofthecompositematerialswasalsostudied.Theresultsshowedthattheadditionofgrapheneimprovedthemechanicalpropertiesandwearresistanceofthecompositematerials.Themaximumimprovementwasachievedwithamassfractionof2%graphene.Thehardnessofthecompositematerialincreasedfrom465HVto495HV,animprovementof6.5%.Thetensilestrengthofthecompositematerialincreasedfrom932MPato1060MPa,animprovementof13.7%.Thecompressivestrengthofthecompositematerialincreasedfrom2476MPato2784MPa,animprovementof12.4%.Thewearresistanceofthecompositematerialimprovedfrom0.038to0.018mm3/Nm,areductionof52.6%.

Theimprovementinthemechanicalpropertiesandwearresistanceofthecompositematerialscanbeattributedtothestrengtheningeffectofgraphene.Thehighsurfaceareaofgrapheneprovidesaneffectiveinterfacewiththehigh-entropyalloymatrix,leadingtoenhancedinterfacialbondingandloadtransfer.Thegraphenealsoactsasabarriertopreventthepropagationofcracksinthematrixmaterial,leadingtohighertoughnessandstrength.Theadditionofgraphenealsoresultsintheformationofafinermicrostructure,whichleadstoareductioninthesizeofdefectsandenhancesthestrengthandhardnessofthecompositematerial.

Inconclusion,graphene/Ni35Co30Cu20Fe15high-entropyalloy-basedcompositematerialsweresuccessfullyprepared,andtheeffectofdifferentmassfractionsofgrapheneontheirpropertieswasinvestigated.Theresultsshowedthattheadditionofgrapheneimprovedthemechanicalpropertiesandwearresistanceofthecompositematerials,withthemaximumimprovementachievedwithamassfractionof2%graphene.ThisstudyprovidesabasisforfutureresearchandapplicationofthesecompositematerialsAsapromisingclassofmaterials,high-entropyalloys(HEAs)haveattractedmuchattentionduetotheiruniqueproperties,includinghighstrength,excellentcorrosionresistance,andgoodwearresistance.However,therearestillsomelimitationsthatneedtobeovercome,suchastheirlowductilityandlowthermalstability.Toaddresstheseissues,researchershaveexploredvariousmethodstoimprovethepropertiesofHEAs,includingtheadditionofreinforcementmaterialssuchasgraphene.

Grapheneisatwo-dimensional(2D)materialwithahexagonallatticestructurecomposedofsp2hybridizedcarbonatoms.Ithasexcellentmechanicalandelectricalproperties,includinghighstrength,highthermalconductivity,andhighelectricalconductivity.Moreover,grapheneislightweightandhasalargesurfacearea,makingitanidealcandidateforimprovingthepropertiesofHEAs.

Inthisstudy,researcherspreparedgraphene/Ni35Co30Cu20Fe15compositematerialsbyapowdermetallurgy(PM)process.ThegraphenewasaddedtotheHEAmatrixindifferentmassfractions(0%,0.5%,1%,2%,and3%)toinvestigatetheeffectofgrapheneonthepropertiesofthecompositematerials.

TheresultsshowedthattheadditionofgraphenetotheHEAmatriximprovedthemechanicalpropertiesofthecompositematerials.Specifically,theadditionof2%grapheneresultedinasignificantincreaseintheyieldstrength,ultimatetensilestrength,andhardnessofthecompositematerials.Theimprovementinmechanicalpropertieswasattributedtothestrengtheningeffectofgraphene,whichcaneffectivelyinhibitdislocationmovementandgraingrowth.

Inadditiontothemechanicalproperties,thewearresistanceofthecompositematerialswasalsosignificantlyimprovedbytheadditionofgraphene.Thewearratedecreasedwithincreasinggraphenecontent,andthelowestwearratewasachievedwith2%graphenecontent.Theimprovementinwearresistancewasattributedtothehighhardnessandexcellentlubricationpropertiesofgraphe