以羧甲基纤维素(CMC)为黏结剂, 通过挤出成型的方式制备氮化硅陶瓷管材, 并研究了黏结剂含量对陶瓷管材生坯性能的影响, 烧结温度对氮化硅陶瓷相对密度、弯曲强度和微观形貌的影响, 以及氮化硅陶瓷的高温强度性能。结果表明: 黏结剂含量为7%(质量分数)时, 可制得干燥收缩均匀、表面光滑、无微裂纹的陶瓷管材生坯; 烧结温度在1 740 ℃时, 氮化硅陶瓷的相对密度和弯曲强度达到最大值, 分别为96%和(684±23) MPa, 其1 200 ℃时的弯曲强度达(380±21) MPa, 具有良好的高温强度性能。

Silicon nitride ceramic pipes were prepared by extrusion with carboxymethyl cellulose (CMC) as the binder. The effect of binder content on the performance of green ceramic pipes was studied. The effect of sintering temperature on the relative density, flexural strength and microstructure of silicon nitride ceramics was studied. At the same time, the high temperature strength performance of silicon nitride ceramics was studied. The results show that with the binder content of 7% (mass fraction), the green ceramic pipe can dry and shrink evenly, and the surface is smooth without micro-cracks. At the sintering temperature of 1 740 ℃, the bulk density and flexural strength of silicon nitride ceramics reach the maximum value, which are 96% and (684±23) MPa, respectively. And the flexural strength reaches (380±21) MPa at 1 200 ℃, silicon nitride ceramics show a good high temperature strength performance.