摘要
本文采用粉末冶金法中的叠层法在2000℃,40MPa的热压烧结条件下设计制备了无宏观缺陷的几类具有不同叠层数的块体SiC/C功能梯度材料(FGM)。所得样品结构的SEM图表明材料总体梯度特征显著,相比四层FGM样品,八层FGM样品梯度过渡趋于连续,其相邻层间界面相对模糊淡化,界面处的结合性能良好,十一层FGM样品梯度过渡更加连续线性,相邻层间界面已基本消失。500℃-室温循环淬水实验和有限元理论模拟均表明八层及大于八层的SiC/C FGM体系有效地缓和了内部热应力,具有良好的抗热震性能。
SiC/C bulk functionally graded materials （FGMs） with different number of graded layers（N） were designed and fabricated successfully by power stacking and hot-press sintering under a pressure of 40MPa at 2000℃. SEM micrographs showed that all SiC/C FGMs as received had excellent gradient characteristics. Compared with that of four-layered （N = 4） FGM, gradient characteristics of eight-layered （N = 8） FGM had a continuous trend, and its interfaces between the adjacent layers faded out gradually and tightly combined, furthermore, that of eleven-layered FGM became more linearly continuous gradient, and its interfaces as a whole disappeared. Thermal shock resistance of SiC/C FGM was repeatedly tested by water quenching with the temperature difference of 500℃. It seems that SiC/C FGM with N ≥ 8 has better thermal shock resistance, and no crack occurs after 90 times quenching.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2007年第1期9-13,共5页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(10205023)
