Properties of Si3N4 based nanocomposites prepared by pressureless sintering method
Si3N4 based nanocomposites were prepared with nano-sized amorphous SiO2 and Si3N4 powders by pressureless sintering method.The microstructures,phase composition,mechanical and dielectric properties of the nanocomposites were investigated.The scanning electrical microscope (SEM) photographs reveal that the grains are big and elongated.The X-ray diffraction (XRD) analysis shows that the main crystalline phase in the composites is Si2N2O formed during the sintering process.More β-Si3N4 phases were retained in the nanocomposites with the increase amount of the amorphous Si3N4 powders and no phase of SiO2 were observed.The densities and the strength of the nanocomposites decreased with the increase of amorphous SiO2 content.Despite low density,the flexural strengths of the composites reaches 220MPa and the ceramic has excellent dielectric properties with dielectric constant as low as 3.2-4.7 and dielectric loss in the range 2.6-3.9×10-3.
Si3N4 based nanocomposites Microstructure Strength Dielectric constant Dielectric loss
Mingli LI Qiong YU Ying XU Qingguo LU Chunjiang ZHOU
Ningbo Branch of China Academy of Ordnance Science, Ningbo 315103, China
国际会议
西安
英文
53-56
2012-08-24（万方平台首次上网日期，不代表论文的发表时间）