In situ synthesis of TiB2-TiC0.8-4Ovol%SiC by hot pressing
TiB2-TiC0.8-40vol%SiC multiphase ceramics were prepared by in-situ hot-pressing sinter ing.The phase composition and microstructures of the materials were characterized by optical mic oscope, X-ray diffraction and scanning electron microscopy.The effects of sintering temperature on the phases, microstructures and mechanical properties of the ceramics were investigated.The results show that density, bending strength and fracture toughness of the ceramics are increased with the elevation of sintering temperature (1800-1950℃).High densified TiB2-TiC0.8-40vol%SiC multipha se ceramics and optimized microstructure is obtained by sintering at 1900℃, in which the uniform distribution of lath-shape TiB2 and bulk TiC0.8 grains can be observed obviously.Nano-SiC particles distributed dispersively in the TiB2 and TiC0.8 grains and at boundaries.The Vickers hardness, fract ure toughness, flexural strength and electrical conductivity of the TiB2-TiC0.8-40vol%SiC multipha se ceramics sintered at 1900℃ are 24.055GPa, 8.27+l.0MPa.m1/2, 516.69MPa and 2.2×106S.m-1,respectively.However, up to 1950℃, TiB2 and TiC0.8 grains gradually grew up, the bending stren gth of multiphase ceramics was decreased greatly.In addition, TiB2, TiC0.8 and SiC particles were incorporated together to improve the particulate strength and toughness of composite material by the synergistic mechanism effects among the crystal phases in the multiphase ceramics, such as crack deflection, grains pull-out and fine-grain toughening.
in-situ synthesis hot-pressing multiphase ceramics TiB2-TiC0.8-SiC
SUN Peiqiu ZHU Degui JIANG Xiaosong SUN Hongliang Chen Song
Key Laboratory of Advanced Technology of Materials Ministry of Education,Southwest Jiaotong University,Chengdu 610031,P.R.of China
国际会议
香港
英文
179-187
2013-06-25（万方平台首次上网日期，不代表论文的发表时间）