摘要
以不同C/Si O2的碳化稻壳为硅源、碳源和成孔剂,添加α-Si3N4和少量烧结助剂,利用碳热还原氮化法原位制备多孔氮化硅陶瓷,研究了不同C/Si O2和烧结温度对多孔陶瓷相组成、显气孔率、抗弯强度和微观结构等性能的影响。结果表明:当选用碳化稻壳C/Si O2(质量比)为0.5和0.7时,在1450-1500℃的试样中有α-Si3N4和β-Si3N4,在1550℃的试样中只有β-Si3N4。C/Si O2为0.7、1450-1550℃下制备出多孔氮化硅陶瓷,其气孔率为52.53%-38.48%,抗弯强度为44.07-83.40 MPa;1550℃制备的多孔β-Si3N4陶瓷中孔隙分布均匀,孔径约为2μm,β-Si3N4呈团簇状生长,长径比约为6-8。
The porous Si3N4 ceramics were directly fabricated by carbothermal reduction and nitridation method which carbonized rice husks with different ratios of C / Si O2( mass ration) as silica source,carbon source and pore forming agent,with assistant of α-Si3N4 and a few of sintering additives. The influences of different rations of C / Si O2 as well as sintering temperature on the phase compositions,apparent porosity,flexural strength and microstructure of porous Si3N4 ceramics were studied. The results reveal that α-Si3N4 phase and β-Si3N4 appear in as-prepared samples when sintering temperatures are in the range of 1450-1500 ℃ with ration of C / Si O2 is 0. 5 or 0. 7. When sintering temperature is 1550 ℃,only β-Si3N4 appears in samples. When the ration of C / Si O2 is 0. 7 and sintering temperatures are in the range of 1450-1550 ℃,the pure phase of porous Si3N4 ceramics are prepared with the porosity of 52. 53%-38. 48% and flexural strength of 44. 07-83. 40 MPa. The best sintering temperature is 1550 ℃,the sample shows uniform distribution porosity with the pore diameter about 2 μm. Also,β-Si3N4 phase grow in cluster with aspect ratio of 6-8.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2015年第9期2484-2489,共6页
Journal of Synthetic Crystals
基金
江苏省教育厅高校自然科学重大基础研究项目(12KJA430006)
关键词
C/SiO2
烧结温度
稻壳
多孔氮化硅陶瓷
C/SiO2
sintering temperature
rice husk
porous silicon nitride ceramic