Synthesis,microstructure,and properties of high purity Mo_(2)TiAlC_(2) ceramics fabricated by spark plasma sintering

作     者：Yunhui NIU Shuai FU Kuibao ZHANG Bo DAI Haibin ZHANG Salvatore GRASSO Chunfeng HU 

作者机构：State Key Laboratory of Environment-Friendly Energy MaterialsSouthwest University of Science and TechnologyMianyang 621010China Key Laboratory of Advanced Technologies of MaterialsMinistry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyang 621900China 

出 版 物：《Journal of Advanced Ceramics》 (先进陶瓷（英文）)

年 卷 期：2020年第9卷第6期

页      面：759-768页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the Thousand Talents Program of Sichuan Province the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials(17kffk01) the Outstanding Young Scientific and Technical Talents in Sichuan Province(2019JDJQ0009) the National Natural Science Foundation of China(Nos.51741208 and 52072311) 

主　　题：MAX phase Mo_(2)TiAlC_(2) synthesis microstructure properties 

摘      要：The synthesis,microstructure,and properties of high purity dense bulk Mo_(2)TiAlC_(2) ceramics were *** purity Mo_(2)TiAlC_(2) powder was synthesized at 1873 K starting from Mo,Ti,Al,and graphite powders with a molar ratio of 2:1:1.25:*** synthesis mechanism of Mo_(2)TiAlC_(2) was explored by analyzing the compositions of samples sintered at different *** was found that the Mo_(2)TiAlC_(2) phase was formed from the reaction among Mo3Al2C,Mo2C,TiC,and *** Mo_(2)TiAlC_(2) bulk sample was prepared by spark plasma sintering(SPS)at 1673 K under a pressure of 40 *** relative density of the dense sample was 98.3%.The mean grain size was 3.5μm in length and 1.5μm in *** typical layered structure could be clearly *** electrical conductivity of Mo_(2)TiAlC_(2) ceramic measured at the temperature range of 2-300 K decreased from 0.95×10^(6) to 0.77×10^(6)Ω^(-1)·m^(-1).Thermal conductivity measured at the temperature range of 300-1273 K decreased from 8.0 to 6.4 W·(m·K)^(-1).The thermal expansion coefficient(TEC)of Mo_(2)TiAlC_(2) measured at the temperature of 350-1100 K was calculated as 9.0×10^(-6) K^(-1).Additionally,the layered structure and fine grain size benefited for excellent mechanical properties of low intrinsic Vickers hardness of 5.2 GPa,high flexural strength of 407.9 MPa,high fracture toughness of 6.5 MPa·m^(1/2),and high compressive strength of 1079 *** at the indentation load of 300 N,the residual flexural strength could hold 84% of the value of undamaged one,indicating remarkable damage ***,it was confirmed that Mo_(2)TiAlC_(2) ceramic had a good oxidation resistance below 1200 K in the air.