纳米金属材料的界面力学行为研究

《纳米金属材料的界面力学行为研究》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、第50卷第2期Vol.50No.22014年2月第183-190页ACTAMETALLURGICASINICAFeb.2014pp.183-190纳米金属材料的界面力学行为研究*魏宇杰(中国科学院力学研究所非线性力学国家重点实验室,北京100190)摘要将常规多晶材料的粗晶粒尺寸缩小到纳米尺度时,这些纳米晶体材料会呈现出与其对应的粗晶材料迥异的物理现象.与材料力学行为最相关的是强度及塑形变形机理这两个方面.考虑到晶界的变形与破坏可能是纳米晶体材料低塑性的根源,克服纳米晶体材料中强度与韧性之间存在的“熊掌和鱼不可兼得”的问题,也通常称为晶界工程.在众多的晶界中

2、,孪晶界面被发现可同时保持材料的强度和韧性.本文主要就纳米金属材料中界面的力学行为做一个简要综述,包含晶界的强化力学机理以及新型孪晶界面的力学行为与揭示内在尺度效应的模型研究.关键词纳米晶体,晶界/孪晶界,强度/塑性,力学模型中图法分类号TG113.2文献标识码A文章编号0412-1961(2014)02-0183-08INVESTIGATIONOFMECHANICALBEHAVIOROFINTERFACESINNANOSTRUCTUREDMETALSWEIYujieStateKeyLaboratoryofNonlinearMechanics,InstituteofMe

3、chanicas,ChineseAcademyofSciences,Beijing100190Correspondent:WEIYujie,professor,Tel:(010)82544169,E-mail:yujie_wei@lnm.imech.ac.cnSupportedbyNationalBasicResearchProgramofChina(No.2012CB937500),NationalNaturalScienceFoundationofChina(Nos.11021262and11272327)andProgramof“OneHundredTalente

4、dPeople”ofChineseAcademyofSciencesManuscriptreceived2013-12-19,inrevisedform2014-01-06ABSTRACTWhengrainsizesofcrystalsaredowntonano-scale,theso-callednanocrystallinematerialsexhib-itdistinctphysicalpropertiesincontrasttotheirconventionalcounterparts.Thestrengthandplasticdeformationmechan

5、ismswereamongthemostbroadlyinvestigatedpropertiesfrommechanicalsociety.Sincedeformationandpre-maturefailureininterfaces(includinggrainboundaries,twinboundaries,andinterfacesbetweendifferentme-dia)couldbetheoriginoflowductilityinnanocrystallinematerials,theefforttoevadethestrength-ductili

6、tytrade-offdilemmainnanocrystallinematerials,bytuningtheirinterfacialstructures/properties,isusuallycalledasinterfa-cialengineering.Twinboundariesstandoutamongallpossibleboundarystructuresfortheircapabilitytoenhancestrengthandretainductilityofcrystallinemetals.Inthispaper,currentundersta

7、ndingaboutthemechanicalbehav-iorassociatedwithinterfacesinnanostructuredmetalsisreviewed,withafocusonthestrengtheningmechanismsplayedbytwin/grainboundariesandcurrentphysicalmodelstoshedlightonthesize-effectinducedbygrainsizesandtwinthicknesses.KEYWORDSnanocrystal,grainbou