Superior synergistic oxidation resistance of medium-entropy carbide ceramic powders rather than multi-phase carbide ceramic powders  

作　　者：Jiachen Li Fanyu Lu Tao Li Yanqin Fu Junhao Zhao Junshuai Lv Yulei Zhang 

机构地区：[1]Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials,State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China

出　　处：《Journal of Advanced Ceramics》2024年第8期1223-1233,共11页先进陶瓷（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.52130205,52302091,and 52293373);the National Key R&D Program of China(No.2021YFA0715803);the Joint Fund of Henan Province Science and Technology R&D Program(No.225200810105);the ND Basic Research Funds of Northwestern Polytechnical University(No.G20022WD).

摘　　要：To date,some questions about medium-entropy carbide ceramics and the corresponding multi-phase carbide ceramics with the same cations and proportions remain unclear.Regarding oxidation behavior,do both have synergistic oxidation abilities and what role does entropy stabilization play in medium-entropy carbides?In this work,the oxidation behaviors of HfC-ZrC-TiC multi-phase carbide(HZT-MPC)and(Hf_(1/3)Zr_(1/3)Ti_(1/3))C medium-entropy carbide(HZT-MEC)powders were investigated.After thermogravimetry(TG)oxidation,the TG curve of HZT-MPC had a bimodal distribution.The"preferential oxidation"of HfC/ZrC occurred within HZT-MPC,followed by the formation of multi-phase oxides(HfO_(2),ZrO_(2),and TiO_(2)).The uneven compositional distribution slowed their solid solution reactions to form Ti-doped(Hf,Zr)O_(2) and(Hf,Zr)TiO_(4).The TG curve of HZT-MEC had a single peak.A uniform compositional distribution at the atomic scale promoted the rapid interdiffusion of oxides,forming Ti-doped(Hf,Zr)O_(2) and(Hf,Zr)TiO_(4) without ZrO_(2),HfO_(2),and TiO_(2) after TG oxidation.Additionally,HZT-MEC had a higher onset oxidation temperature(To;470℃)than did HZT-MPC(430℃),and the TG single peak of HZT-MEC was between the TG bimodal peaks of HZT-MPC.Therefore,HZT-MEC showed superior oxidation resistance compared to HZT-MPC,which was attributed to the entropy stabilization effect of HZT-MEC suppressing the"preferential oxidation"of HfC/ZrC and the"delayed oxidation"of TiC,promoting the synergistic oxidation ability of multiple principal elements.

关 键 词：medium-entropy carbide multi-phase carbide synergistic oxidation ability oxidation resistance 

分 类 号：TQ174.7[化学工程—陶瓷工业]