Ultra-strong and ductile precipitation-strengthened high entropy alloy with 0.5%Nb addition produced by laser additive manufacturing  

作　　者：Wei Zhang Ali Chabok Hui Wang Jiajia Shen J.P.Oliveira Shaochuan Feng Nobert Schell Bart J.Kooi Yutao Pei 

机构地区：[1]Advanced Production Engineering,Engineering and Technology Institute Groningen,Faculty of Science and Engineering,University of Groningen,Nijenborgh 4,9747 AG,the Netherlands [2]Nanostructured Materials and Interfaces,Zernike Institute for Advanced Materials,Faculty of Science and Engineering,University of Groningen,Nijenborgh 4,9747 AG,the Netherlands [3]UNIDEMI,Department of Mechanical and Industrial Engineering,NOVA School Science and Technology,Universidade NOVA de Lisboa,Caparica 2829-516,Portugal [4]CENIMAT/I3N,Department of Materials Science,NOVA School of Science and Technology,Universidade NOVA de Lisboa,2829-516 Caparica,Portugal [5]School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China [6]Institute of Materials Physics,Helmholtz-Zentrum Hereon,Max-Planck-Str.1,Geesthacht,D-21502,Germany

出　　处：《Journal of Materials Science & Technology》2024年第20期195-211,共17页材料科学技术（英文版）

基　　金：WZ acknowledges the China Scholarship Council for her PhD grant(CSC No.201906250212);YP acknowledges financial support by Samenwerkingsverband Noord-Nederland(SNN)within the pro-gram“3D Print Kompas”;JPO and JS acknowledge Fundação para a Ciência e a Tecnologia(FCT-MCTES)for its financial support via the project UID/00667/2020(UNIDEMI);JPO acknowledges fund-ing by national funds from FCT-Fundação para a Ciência e a Tecnologia,I.P.,in the scope of the projects Nos;LA/P/0037/2020,UIDP/50025/2020,and UIDB/50025/2020 of the Associate Labo-ratory Institute of Nanostructures,Nanomodelling and Nanofabri-cation–i3N.JS acknowledges the China Scholarship Council for her PhD grant(CSC No.201808320394);The authors acknowledge DESY(Hamburg,Germany),a member of the Helmholtz Associ-ation HGF,for the provision of experimental facilities.Beamtime was allocated for proposal I-20210899 EC;The research leading to this result has been supported by the project CALIPSOplus un-der Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020;SF acknowledges fi-nancial support from the National Natural Science Foundation of China(No.52105318 and 52311530340);"Chunhui Plan"Col-laborative Research Project of the Ministry of Education,China(HZKY20220023);This research was carried out under project number S17024o in the framework of the Partnership Program of the Materials Innova-tion Institute M2i(www.m2i.nl);the Netherlands Organization for Scientific Research(www.nwo.nl).

摘　　要：Achieving a superior strength-ductility combination for fcc single-phase high entropy alloys(HEAs)is challenging.The present work investigates the in-situ synthesis of Fe_(49.5)Mn_(30)Co_(10)Cr_(10)C_(0.5)interstitial solute-strengthened HEA containing 0.5 wt.%Nb(hereafter referred to as iHEA-Nb)using laser melt-ing deposition(LMD),aiming at simultaneously activating multiple strengthening mechanisms.The effect of Nb addition on the microstructure evolution,mechanical properties,strengthening and deformation mechanisms of the as-deposited iHEA-Nb samples was comprehensively evaluated.Multiple levels of het-erogeneity were observed in the LMD-deposited microstructure,including different grain sizes,cellular subgrain structures,various carbide precipitates,as well as elemental segregation.The incorporation of Nb atoms with a large radius leads to lattice distortion,reduces the average grain size,and increases the types and fractions of carbides,aiding in promoting solid solution strengthening,grain boundary strengthening,and precipitation strengthening.Tensile test results show that the Nb addition significantly increases the yield strength and ultimate tensile strength of the iHEA to 1140 and 1450 MPa,respectively,while maintaining the elongation over 30%.Deformation twins were generated in the tensile deformed samples,contributing to the occurrence of twinning-induced plasticity.This outstanding combination of strength and ductility exceeds that for most additively manufactured HEAs reported to date,demon-strating that the present in situ alloying strategy could provide significant advantages for developing and tailoring microstructures and balancing the mechanical properties of HEAs while avoiding conventional complex thermomechanical treatments.In addition,single-crystal micropillar compression tests revealed that although the twining activity is reduced by the Nb addition to the iHEA,the micromechanical prop-erties of grains with different orientations were significantly enhanced.

关 键 词：Laser additive manufacturing High entropy alloy In situ alloying Precipitation strengthening Deformation mechanism Mechanical properties 

分 类 号：TG14[一般工业技术—材料科学与工程]