B对WC-20%Co硬质合金微观结构与力学性能的影响刘国强1,2（1.中南大学粉末冶金研究院，湖南长沙410083；2.株洲硬质合金集团有限公司，湖南株洲412000）摘要硬质合金中微量元素的添加主要集中在V、Ta、Hf、Ce等金属元素，非金属元素应用较少，主要有B等元素。非金属元素B引入硬质合金方式主要有表面渗硼和在原料粉末中添加，本文以化学性能稳定的B4C为添加剂，在WC-20%Co(YG20C)硬质合金混合料制备过程中进行添加，采用气压烧结制备出含硼WC-20%Co硬质合金。研究了B添加（0.01%、0.03%、0.06%，质量分数）对WC-20%Co硬质合金组织结构及力学性能的影响。实验结果表明：B含量增加使YG20C合金晶粒度分布趋向不均匀，当B添加量为0.06%时，其晶粒度呈现双峰分布趋势，同时，随着B含量的增加，YG20C合金硬度提高；当B添加量为0.01%时，合金的断裂韧性最佳（16.43MPa·m1/2）。关键词硬质合金；硼元素；力学性能；微观组织EffectofBorononMicrostructureandMechanicalPropertiesofWC-20%CoCementedCarbidesLiuGuoqiang1,2（1.PowderMetallurgyResearchInstitute,CentralSouthUniversity,ChangshaHunan410083,China;2.ZhuzhouCementedCarbideGroupCo.Ltd.,ZhuzhouHunan412000,China）ABSTRACTThetraceelementsaddedintocementedcarbidesmainlyincludeV,Ta,Hf,Ceandothermetallicelements,andtheapplicationofnon-metallicelementsisless,mainlyincludingelementssuchasBwhichisintroducedintocementedcarbidesmainlyintwoways:boronizingandaddingitintorawpowders.Inthispaper,B4CwithstablechemicalpropertiesisaddedastheadditiveduringthepreparationoftheWC-20%Co(YG20C)cementedcarbidemixture.Theboron-containingWC-20%Cocementedcarbideispreparedbygas-pressuresintering.TheeffectoftheadditionofB(0.01%,0.03%,0.06%,massfraction)onthestructureandmechanicalpropertiesoftheWC-20%Cocementedcarbideisstudied.TheexperimentalresultsshowthattheincreaseintheBcontentleadstothenonuniformityofthegrainsizedistributionoftheYG20Ccementedcarbide.When0.06%ofBisadded,thegrainsizeofthecementedcarbideisinabimodaldistribution.AstheBcontentrises,thehardnessoftheYG20Ccementedcarbideincreases.When0.01%ofBisadded,thecementedcarbidehastheoptimalfracturetoughness(16.43MPa.m1/2).KEYWORDScementedcarbide;elementB;mechanicalproper...
