Titanium nitrides as novel reactants for in-situ synthesis of TiB_(2)-based composites with improved properties  

作　　者：Ji Zou Huayue Liang Jingjing Liu Weimin Wang Fan Zhang Wei Ji Zhengyi Fu 

机构地区：[1]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China [2]Hubei Longzhong Laboratory,Xiangyang 441000,China [3]School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China

出　　处：《Journal of Materials Science & Technology》2023年第14期48-55,共8页材料科学技术（英文版）

基　　金：This work was financially supported by the National Nat-ural Science Foundation of China(Nos.52022072,51972243,92060202 and 52102029);the National Key R&D Programs(No.2021YFB3701400);Hubei Provincial Natural Science Foundation of China(Distinguished Young Scholars 2022CFA042);Independent Innovation Projects of the Hubei Longzhong Laboratory(2022ZZ-10)were also acknowledged.

摘　　要：A novel in-situ reactive approach based on the reactions among TiN,aluminum and boron has been developed to synthesize TiB_(2)-based composites including TiB_(2)-h BN(TB)and TiB_(2)-h BN-AlN(TBA).Fully dense ceramics with fine-grained microstructure were successfully obtained via spark plasma sintering at 1850℃/60 MPa/5 min.Microstructure analysis suggests h BN flakes were homogenously distributed in the TiB_(2)matrix.For AlN,however,they were elongated into plate-like grains during sintering,in which lots of defects in terms of stacking faults and twinning structures were observed.The mechanical and thermophysical properties of as-sintered ceramics were comprehensively investigated and compared.In-corporating AlN significantly improved the flexure strength,hardness,fracture toughness and thermal conductivity of TiB_(2)-h BN ceramics.The electrical conductivity of TB(3.06×10^(6)S/m)is larger than that of TBA(2.35×10^(6)S/m)at room temperature,but the value(6×10^(5)S/m)was lower than that of TBA(6.9×10^(5)S/m)at 1173 K.Based on the measurement of electrical and thermal conductivity,electron and phonon contributions to thermal conductivities of TB and TBA were calculated and their temperature dependences were illustrated.

关 键 词：Borides Microstructure Spark plasma sintering Mechanical property Thermo-physics property 

分 类 号：TQ174.75[化学工程—陶瓷工业]