等摩尔比多元过渡金属碳化物固溶体陶瓷的抗氧化性能  

Oxidation Resistance of Equimolar Multicomponent Transition Metal Carbide Solid Solution

作　　者：闫子豪[1] 刘吉轩 彭湃 张国军 YAN Zi-Hao;LIU Ji-Xuan;PENG Pai;ZHANG Guo-Jun(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Institute of Functional Materials,College of Materials Science and Engineering,Donghua University,Shanghai 201620,China; Engineering Research Center of Advanced Glass Manufacturing Technology,Ministry of Education,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学纤维材料改性国家重点实验室功能材料研究中心材料科学与工程学院,上海201620 [2]东华大学先进玻璃制造技术教育部工程研究中心,上海201620

出　　处：《现代技术陶瓷》2024年第6期541-557,共17页Advanced Ceramics

基　　金：国家自然科学基金(52371023、52032001);中央高校基本科研业务费专项资金(2232024G-07)

摘　　要：过渡金属碳化物及其固溶体具有高熔点和优异的力学性能,在机械加工、航天等领域有着广阔的应用前景。但是,这类材料相对较低的抗氧化性能,限制了其进一步发展与应用。本文以ZrC为基础组元,通过引入IVB、VB族过渡金属元素Ti、Hf、Nb、Ta,采用碳热还原合成了过渡金属碳化物固溶体粉末,并利用放电等离子体烧结技术制备了(Ti_(1/2)Zr_(1/2))C、(Ti_(1/3)Zr_(1/3)Hf_(1/3))C、(Ti_(1/4)Zr_(1/4)Hf_(1/4)Nb_(1/4))C、(Ti_(1/4)Zr_(1/4)Hf_(1/4)Ta_(1/4))C、(Ti_(1/4)Zr_(1/4)Nb_(1/4)Ta_(1/4))C、(Zr_(1/4)Hf_(1/4)Nb_(1/4)Ta_(1/4))C、(Ti_(1/5)Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5))C等7种等摩尔比多元过渡金属碳化物固溶体(TMC_(ss))陶瓷,并研究了其在1200℃流动空气中的抗氧化性能,考察了组元数量和元素组成等对材料的氧化行为的影响规律。结果显示,所制备的材料均为单相的NaCl型立方结构固溶体。随着组元数的增多,材料的构型熵增加,材料氧化后,其氧化层厚度和单位面积氧化增重均变小。在构型熵相同的4种四元TMC_(ss)陶瓷中,含有Nb元素的TMC_(ss)陶瓷,表现出了更好的抗氧化性能。构型熵最大且含有Nb元素的(Ti_(1/5)Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5))C五元TMC_(ss)陶瓷经1200℃的流动空气中氧化10 min后,其氧化层厚度和单位面积氧化增重分别为21.75μm和1.62 mg/cm^(2),显著低于其它二元、三元、四元TMC_(ss)陶瓷。分析认为,构型熵的增加使得TMC_(ss)的热力学稳定性提高,同时,低熔点氧化产物Nb_(2)O_(5)和Zr_(6)Nb_(2)O_(17)等对材料表面氧化层的致密化具有促进作用,两种因素协同改善了材料的抗氧化性能。研究结果可为新型抗氧化过渡金属碳化物陶瓷的组分设计提供一定的参考。transition metal carbides and their solid solutions have high melting points and excellent mechanical properties,which have broad application prospects in the machining and aerospace industries.However,their low oxidation resistance at high temperatures limits further development and applications.In this work,using ZrC as the basic group component,by introducing IVB and VB group transition metal elements Ti,Hf,Nb and Ta,the binary,ternary,quaternary and quinary equimolar transition metal carbide solid solution powders are synthesized by carbothermal reduction process and their dense ceramics with compositions of(Ti_(1/2)Zr_(1/2))C、(Ti_(1/3)Zr_(1/3)Hf_(1/3))C、(Ti_(1/4)Zr_(1/4)Hf_(1/4)Nb_(1/4))C、(Ti_(1/4)Zr_(1/4)Hf_(1/4)Ta_(1/4))C、(Ti_(1/4)Zr_(1/4)Nb_(1/4)Ta_(1/4))C、(Zr_(1/4)Hf_(1/4)Nb_(1/4)Ta_(1/4))C、(Ti_(1/5)Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5))C are prepared by spark plasma sintering.The oxidation resistance of the ceramics at 1200℃in flowing air is evaluated.The effects of the component number and the transition metal elements on the materials'oxidation behavior are analyzed.The results show that all the samples are single-phase solid solutions with NaCl-type cubic crystal structure.As the component number increases,the mixing entropy of the materials increases,and the thickness of the oxide layer and the oxidation weight gain rate of the materials after the oxidation test becomes smaller.Among the four quaternary carbide solid solution ceramics with the same mixing entropy,the carbide solid solution ceramics containing Nb elements showed better oxidation resistance.After oxidized at 1200℃for 10 min in flowing air,fivecomponent transition metal carbide solid solution(Ti_(1/5)Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5))C ceramics with the largest mixing entropy and containing Nb elements shows an oxide layer thickness 21.5μm and a mass gain per unit surface area of 1.62 mg/cm^(2),respectively,which were significantly lower than those of other binary,ternary,and quaternary equimolar carbide solid solution ceram

关 键 词：过渡金属碳化物 固溶体 高熵碳化物 高熵效应 氧化 

分 类 号：TB331[一般工业技术—材料科学与工程]