【摘要】 利用ＴＥ１０３单模腔微波烧结系统对添加６％（Ｙ２Ｏ３＋Ａｌ２Ｏ３）的α、β－Ｓｉ３Ｎ４粉的微波加热特征进行了研究。通过选择合理的保温材料和烧结工艺，获得了较高密度、结构均匀的氮化硅烧结体。实验发现，对于粉末为α－Ｓｉ３Ｎ４的试样，在相变发生的温度范围内，相变的发生比致密化进程更早，而且发生在一个相对更低的温度，研究结果也表明，在微波烧结中相变促进致密化进程。在较短的时间内获得较高的密度和较好的力学性能，氮化硅的微波烧结显示了加强的烧结行为，这种加强的烧结行为来自快速加热中温度梯度产生的瞬间应力。更多还原

【Abstract】 Dense silicon nitride from α and β-Si 3N 4 powders with 6wt%(Y 2O 3+Al 2O 3) additives were fabricated in a TE 103 single mode cavity microwave sintering system operating at 2 45 GHz. Proper packing powders and sintering measures were used. The sintering behavior from both powders was investigated with special interests in the evolution of α to β-Si 3N 4 phase transformation, densification and microstructure development. Densities of about 96.7% T.D.and 95% T.D.were separately achieved by microwave sintering of α and β-Si 3N 4 powders, and it was also observed that α to β conversion was more rapid than densification process in microwave heating of α-Si 3N 4. It is evident that microwave sintering of Si 3N 4 showed enhanced sintering behavior, and transient stress caused by temperature gradient is believed to be responsible for enhanced sintering. Mechanical properties of sintered specimen were also reported.更多还原