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1、幾種AlCrNbTiVSi高熵合金的微觀組織研究/汪燕青等幾種AICrNbTiVSi高熵合金的微觀組織研究汪燕青,劉兆剛(1寧夏大學(xué)物理電氣信息學(xué)院,銀川750021;2國(guó)家鉭鈮特種金屬材料工程技術(shù)研究中心,石嘴山753000)摘要利用真空非自耗電弧爐熔煉了AlCrNbTⅣ等物質(zhì)的量高熵合金鑄錠、AICrNb2Ti2Vo.5非等物質(zhì)的量高熵合金和A1CrNb5TiVSi六元合金。分別對(duì)這3種合金進(jìn)行了0M、XRD、SEM和EDS分析;研究了合金中的物相組成、微觀組織和成分分布規(guī)律。實(shí)驗(yàn)結(jié)果表明,AlCrNbTIV高熵合金和A1CrNbzTi
2、zVos高熵合金都只形成了BCC結(jié)構(gòu)高熵固溶相,且未產(chǎn)生金屬間化合物相。而A1CrNbsTIvsi合金盡管配位熵很高,但由于Si的電負(fù)性,生成了離散分布的NbSi3金屬間化合物。對(duì)A1CrNbTiV高熵合金和A1CrNb2Ti2V0.5高熵合金在單個(gè)晶粒中的成分分布進(jìn)行分析,發(fā)現(xiàn)在高熵效應(yīng)作用下,合金各元素含量波動(dòng)較小,平均偏差均小于2(原子分?jǐn)?shù)),但兩種合金元素含量存在微弱的變化趨勢(shì),如Nb在晶粒中心的含量比晶粒邊緣略高,而另一些元素如Cr則恰好相反,表明在凝固和形核過程中仍然不可忽略元素熔點(diǎn)和原子半徑效應(yīng)。關(guān)鍵詞高熵合金難熔金屬A1Cr
3、NbTiV高熵合金中圖分類號(hào):TG131文獻(xiàn)標(biāo)識(shí)碼:AStudyonMicrostructureofSeveralAICrNbTiVSiHighEntropyAlloysWANGYanqing,LIUZhaogang(1SchoolofPhysicsandElectricalInformation,NingxiaUniversity,Yinchuan750021;2NationalEngineeringResearchCenterofTitaniumandNiobiumMaterial,Shizuishan753000)AbstractTh
4、eequimolarAlCrNbTiVhighentropyalloy,non-equimolarA1CrNb2Ti2Vo5highentropyalloyandA1CrNb5TiVSialloywerepreparedbynon-consumablevacuumarc—meltingfurnace.Theinvestigationsofmicro—structure,phasecompositionandelementdistributionofthethreealloyswerecarriedoutbyOM,XRD,SEMandEDSm
5、ethods.TheresultindicatedthatAlCrNbTiValloyandA1CrNb2TizVo5alloyhadonlyhighentropysolidsolutionphasewithBCCstructure,andnointermetalliccompoundswereformed.TheA1CrNb5TiVsialloyhadtwophasesin—cludingBCCsolidsolutionandIMCofNb5Si3duetohighelectronegativityofSi,althoughitsmixi
6、ngentropyreachedahighleve1.BesidethattheelementsdistributionofA1CrNbTiVandA1CrNbzTi2Vo5insinglegrainanalysisrevealedthat,underhighentropyeffect,thecontentfluctuationsofelementsofthesetwoalloysinsinglegrainwereverysmall,theiraveragedeviationsbelow2at.Buttherewasaveryweaktre
7、ndexistedinthetwoalloysanalyzed,forexamplethecontentsoftheelementNbwerehighincenterofgrainbutlOWontheborder.a(chǎn)ndthecontentstrendofCrwerejusttheopposite.Itimpliedthattheeffectsofelementmeltingpointsandatomicradiuscannotbeignoredinsolidificationprocess.Keywordshighentropyallo
8、ys,refractorymetals,AlCrNbTiVhighentropyalloys能,在能量上更有利于高熵固溶相的形成。利用簡(jiǎn)單的原子0引言格模型,不難推算出合金混合熵