Dynamic recrystallization behavior and strengthening mechanism of a novel Mo-Ti_(3)AlC_(2) alloy at ultrahigh temperature  

作　　者：Lu Yang Xin-Yuan Zheng Yang Zhao Xi-Ran Wang Fang-Nao Xiao Shi-Zhong Wei 

机构地区：[1]School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China [2]National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology,Luoyang 471003,China [3]Department of Applied Mechanics,Univ.Bourgogne FrancheComte,FEMTO-ST Institute,CNRS/UF/ENSMM/UTBM,25000Besangon,France

出　　处：《Rare Metals》2024年第8期3946-3960,共15页稀有金属（英文版）

基　　金：sponsored by National Key R&D Program of China (No.2020YFB2008400);Key Technology and Development Program of Henan Province (No.232102231024)。

摘　　要：Increasing the recrystallization temperature to achieve better high-temperature performance is critical in the development of molybdenum alloys for ultrahightemperature applications,such as the newest generation of multitype high-temperature nuclear reactors.In this study,an innovative strategy was proposed to improve the performance of molybdenum alloys at high temperature by using the two-dimensional MAX(where M is an early transition metal,A is an A-group element and X is C or N)ceramic material Ti_(3)AlC_(2).The relationships between flow stress,strain rate and temperature were studied.The microstructure,distribution of misorientation and evolution of dislocations in the Mo-Ti_(3)AlC_(2) alloy were analyzed.The microscopic mechanism of the Ti_(3)AlC_(2) phase in the molybdenum alloy at high temperatures was clarified.The experimental results showed that the peak flow stress of Mo-Ti_(3)AlC_(2) at 1600℃ reached 155 MPa,which was161.8% greater than that of pure Mo.The activation energy of thermal deformation of Mo-Ti_(3)AlC_(2) was as large as537 kJ·mol~(-1),which was 17.6% more than that of pure Mo.The recrystallization temperature reached 1600℃ or even higher.The topological reaction of the Ti_(3)AlC_(2) phase consumed a large amount of energy at high temperatures,resulting in increases in the deformation activation energy.Nanolayer structures of AlTi_3 and Ti-O Magneli-phase oxides(Ti_nO_(2n-1)) were formed in-situ,which relied on kink bands and interlayer slip,resulting in many dislocations during deformation.Therefore,the special two-dimensional of the structure Ti_(3)AlC_(2) ceramic inhibited the recrystallization behavior of the Mo alloy.The results of this study can provide theoretical guidance for the development of a new generation of molybdenum alloys for use in ultrahigh-temperature environments.

关 键 词：Mo alloy Two-dimensional reinforcement Dynamic recrystallization behavior Hot deformation Mechanical properties 

分 类 号：TL341[核科学技术—核技术及应用] TG146.412[一般工业技术—材料科学与工程]