In order to improve the intrinsic brittleness of TiAl alloys,Ti2AlNb alloys with outstanding ductility and toughness at room temperature,and good high-temperature performance are competitive candidates in constructing the TiAl-based laminated composites.In this work,TiAl/Ti2AlNb laminated composites are successfully synthesized by vacuum hot pressing combined with the foil-foil(sheet)metallurgy.Under the pressure of 65 MPa,different holding time and temperature of hot pressing are tried and the opti-mized fabrication parameter is acquired as 1050℃/120 min/65 MPa.Along with the changes of process-ing parameters,the defect,microstructure,interface,phase transformation and the corresponding me-chanical properties are detailly discussed.The results show that the TiAl/Ti2AlNb laminated composite fabricated at 1050℃for 2 h achieves a good metallurgical interface bonding.The corresponding inter-face microstructure is composed of region I and region Ⅱ.The region Ⅰ consists of O,α2 and B2/β phase,and region Ⅱ is made up of α2.Subsequently,the tensile tests indicate that the composite synthesized at 1050℃for 2 h possesses a maximum strength of 812 MPa and a total elongation of 1.31％at room temperature,and a strength of 539.71 MPa and the highest total elongation of 10.34％at 750℃.The well synergistic deformation ability between the interface and the two base alloys endows the composite an excellent tensile performance.Moreover,the composite processed at 1050℃for 2 h behaves the best fracture toughness in both arrester orientation and divider orientation with the value of 32.6 MPa.m1/2 and 30.1 MPa.m1/2,respectively.The Ti2AlNb alloy in the laminated structure effectively release the stress around the crack tip and plays a role in toughening.Further,crack deflection,crack bridging,crack blunt-ing and fragmentation also make contributions to enhance the fracture toughness of the laminated com-posites.

Donghai Li;Binbin Wang;Liangshun Luo;Xuewen Li;Yanjin Xu;BinQiang Li;Diween Hawezy;Liang Wang;Yanqing Su;Jingjie Guo;Hengzhi Fu

National Key Laboratory for Precision Hot Processing of Metals,School of Materials Science & Engineering,Harbin Institute of Technology,Harbin 150001,China;Key Laboratory for Lightweight Materials,Nanjing Tech University,Nanjing 211816,China;AVIC Manufacturing Technology Institute,Beijing 100024,China;Materials Research Centre,College of Engineering,Swansea University,Bay Campus,Swansea SA1 8EN,UK

材料科学技术（英文版）

[1]Donghai Li;Binbin Wang;Liangshun Luo;Xuewen Li;Yanjin Xu;BinQiang Li;Diween Hawezy;Liang Wang;Yanqing Su;Jingjie Guo;Hengzhi Fu-.Effect of processing parameters on the microstructure and mechanical properties of TiAl/Ti2AlNb laminated composites)[J].材料科学技术（英文版）,2022(14):228-244

Effect,processing,parameters,microstructure,mechanical,properties,TiAl,Ti2AlNb,laminated,composites,In,order,improve,intrinsic,brittleness,alloys,outstanding,ductility,toughness,room,temperature,good,performance,are,competitive,candidates,constructing,this,work,successfully,synthesized,by,vacuum,hot,pressing,combined,foil,sheet,metallurgy,Under,pressure,different,holding,tried,opti,mized,fabrication,acquired,Along,changes,defect,interface,phase,transformation,corresponding,detailly,discussed,results,show,that,fabricated,achieves,metallurgical,bonding,composed,region,consists,B2,made,up,Subsequently,tensile,tests,indicate,possesses,maximum,strength,total,elongation,highest,well,synergistic,deformation,ability,between,two,endows,excellent,Moreover,processed,behaves,best,fracture,both,arrester,orientation,divider,value,m1,respectively,effectively,release,stress,around,crack,tip,plays,role,toughening,Further,deflection,bridging,blunt,fragmentation,also,make,contributions,enhance

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