摘要
以毛竹的炭化物为生物模板材料,采用溶胶-凝胶法对其浸渍一定量的二氧化硅溶胶,应用碳热还原反应制备竹基SiC陶瓷,并对其结构、化学组成和力学性能进行表征。结果表明,煅烧温度和时间决定了陶瓷的物相组成。煅烧温度1450℃、时间5h可使所有的二氧化硅凝胶与炭反应生成SiC。煅烧温度过低、煅烧时间过长或不足均有可能在材料内残留或产生一定量SiO2,在此条件下制备的生物陶瓷实际为SiC和大量自由炭组成的SiC/C复合陶瓷,其中SiC陶瓷主要分布在材料的表层区域;制备的竹基SiC/C复合生物陶瓷的顺纹抗压强度、抗弯强度及抗弯弹性模量均随试样溶胶质量增加率的增高呈先上升后下降的趋势,溶胶质量增加率在10%左右时制得的陶瓷力学性能最佳,并显著优于相应竹炭的力学性能。
Bamboo-based SiC ceramics were prepared by carbothermal reduction reaction between charcoal and silica that was introduced into bamboo through a sol-gel and vacuum/pressure infiltration process. The microstructure, chemical compositions and mechanical performances of the prepared ceramics were characterized. Experimental results showed that the phase compositions of the ceramics were highly dependent on the sintering temperate and time. 1 450 ℃ and 5 h could ensure almost all the SiO2 to be transformed into SiC while lower temperature and longer or shorter time will remain or produce certain quantity of SiO2 in the ceramics. The produced biological ceramic was actually a composite of higher proportional C and SiC, which was mainly formed and distributed on the surface of bamboo carbon. Compression strength, bending MOE and MOR of the composite ceramics were all found to increase and then decrease with the increase of SiO2 weight gain. Optimal mechanical performances were achieved when SiO2 weight gain was 10% and much more superior to those of bamboo carbon.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2012年第1期138-142,共5页
Scientia Silvae Sinicae
基金
"十一五"国家科技支撑课题"竹基新型炭材料制备技术研究"(2006BAD19B06)
