Electron-irradiation-facilitated production of chemically homogenized nanotwins in nanolaminated carbides  

作　　者：Hui Zhang Qianqian Jin Tao Hu Xiaochun Liu Zezhong Zhang Chunfeng Hu Yanchun Zhou Yu Han Xiaohui Wang 

机构地区：[1]Electron Microscopy Center,South China University of Technology,Guangzhou 510640,China [2]School of Emergent Sof Mater,South China University of Technology,Guangzhou 510640,China [3]Center for the Structure of Advanced Matter,School of Electronic Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China [4]Institute of Materials Science and Devices,School of Materials Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China [5]Institute of Metals,Changsha University of Science&Technology,Changsha 410004,China [6]Electron Microscopy for Materials Research(EMAT),University of Antwerp,Antwerp 2020,Belgium [7]Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China [8]School of Materials Science&Engineering,Zhengzhou University,Zhengzhou 4501,China [9]Advanced Membranes and Porous Materials Center,Physical Sciences and Engineering Division,King Abdullah University of Science and Technology,Thuwal 23955-6900,Saudi Arabia [10]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Journal of Advanced Ceramics》2023年第6期1288-1297,共10页先进陶瓷（英文）

摘　　要：Twin boundaries have been exploited to stabilize ultrafine grains and improve mechanical properties of nanomaterials.The production of the twin boundaries and nanotwins is however prohibitively challenging in carbide ceramics.Using a scanning transmission electron microscope as a unique platform for atomic-scale structure engineering,we demonstrate that twin platelets could be produced in carbides by engineering antisite defects.The antisite defects at metal sites in various layered ternary carbides are collectively and controllably generated,and the metal elements are homogenized by electron irradiation,which transforms a twin-like lamellae into nanotwin platelets.Accompanying chemical homogenization,α-Ti_(3)AlC_(2) transforms to unconventionalβ-Ti_(3)AiC_(2).The chemical homogeneity and the width of the twin platelets can be tuned by dose and energy of bombarding electrons.Chemically homogenized nanotwins can boost hardness by~45%.Our results provide a new way to produce ultrathin(<5 nm)nanotwin platelets in scientifically and technologically important carbide materials and showcase feasibility of defect engineering by an angstrom-sized electron probe.

关 键 词：ELECTRON-IRRADIATION MAX phases carbides antisite defects crystal-structure engineering 

分 类 号：TB332[一般工业技术—材料科学与工程]