Microstructural evolution and thermal fatigue damage mechanism of second-phase dispersion strengthened tungsten composites under repetitive thermal loads  

作　　者：Hui Wang Zhuoming Xie Xiang Cheng Ke Jing Linchao Zhang Junfeng Yang Rui Liu Le Han Lei Cao Xianping Wang Qianfeng Fang Changsong Liu Xuebang Wu 

机构地区：[1]Key Laboratory of Materials Physics,Institute of Solid State Physics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China [2]University of Science and Technology of China,Hefei 230026,China [3]Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China

出　　处：《Journal of Materials Science & Technology》2023年第9期221-232,共12页材料科学技术（英文版）

基　　金：supported by the National Key Research and Development Program of China(Nos.2019YFE03110200,2017YFE0302400,and 2019YFE03120001);the National Natural Science Foundation of China(Nos.11735015,52171084,52173303,U1967211);Anhui Provincial Natural Science Foundation(No.1908085J17);the HFIPS Director’s Fund(Nos.YZJJZX202012,YZJJ202206-CX,BJPY2021A05).

摘　　要：In a fusion reactor,plasma-facing tungsten(W)materials inevitably suffer severe thermal shock,and the performance of W materials under repetitive high heat loads is one of the key concerns for long-term stable operation of the reactor.In this work,the microstructural evolution and thermal fatigue resistance of two representative W-0.5 wt.%ZrC(WZC)and W-1.0 wt.% Y_(2)O_(3)(WYO)composites were investigated under cyclic heat loads.Due to the intrinsic properties of ZrC and Y_(2)O_(3)particles such as coefficients of thermal expansion,particle size and distributions in W grains,the WZC composite exhibited a better thermal shock resistance than WYO.After thermal loads with the absorbed power density(APD)≥22 MW/m^(2),WYO showed obvious grain growth,Y_(2)O_(3)particles shedding and degradation of mechanical properties.While,in the case of WZC,these damage behaviors only occurred when APD≥25 MW/m^(2).Furthermore,an interesting crack mechanism in W composites was revealed due to interface debonding and progressive shedding of second-phase particles from the W matrix.The microstructures and tensile properties of the thermally loaded WZC and WYO specimens were also investigated and the correlations between the microstructure evolution and performance degradation are demonstrated.The results are useful for evaluating the thermal fatigue resistance of oxide/carbide dispersion strengthened W composites and their application in future fusion reactors.

关 键 词：TUNGSTEN Thermal loads Microstructure Particle shedding Mechanical properties 

分 类 号：TG146.23[一般工业技术—材料科学与工程]