【摘要】 采用粉末冶金法中的叠层法在2 000℃、40 MPa的热压烧结条件下制备了几类不同层数及成分分布指数的SiC/C功能梯度块体材料(FGM)。所得样品的结构扫描图表明材料总体梯度特征显著,相比四层FGM样品,八层(SF8)FGM样品梯度过渡趋于连续,其不同层间层界面相对模糊化,界面处的结合性能良好,与最初设计相吻合;500℃~室温循环淬水实验表明,采用参数优化设计的SF8(P=0.6)FGM有效地缓和了内部热应力,具有良好的抗热震性能。更多还原

【Abstract】 SiC/C block Functionally graded materials(FGMs) with different layers and compositional distribution factor(P) are designed and fabricated successfully by power stacking and hot-press sintering under a pressure of 40 MPa at 2 000℃.SEM micrographs show that all SiC/C FGMs as received have excellent gradient characteristics compared with that of four-layered FGM.Gradient characteristics of eight-layered FGM have a continuous trend and its interfaces between different layers are crack-free and tightly combined.Thermal shock resistance of SiC/C FGM is repeatedly tested by water quenching with the temperature difference of 500℃.It seems that eight-layered SiC/C FGM(P=0.6) with optimized parameter has better thermal shock resistance and no cracks occur after 90 times quenching.更多还原