烧结温度对气压烧结氮化硅铁显微结构及性能的影响

发布时间：2018-06-03 18:30

  本文选题：氮化硅铁 + 气压烧结　； 参考：《硅酸盐学报》2017年12期

【摘要】：以微米级氮化硅铁为原料、Al_2O_3 Y_2O_3为烧结助剂,采用气压烧结制备氮化硅铁复相陶瓷。通过X射线衍射和扫描电子显微镜对试样的物相组成和显微结构进行了表征,研究了烧结温度对氮化硅铁复相陶瓷成分、显微结构和力学性能的影响。结果表明:烧结温度对于氮化硅铁陶瓷的显微结构和力学性能具有显著影响。随着烧结温度的升高,样品致密度、抗弯强度、断裂韧性先增大后降低,在1 770℃时均达到最大值,密度、抗弯强度和断裂韧性分别达到3.31 g/cm~3、435 MPa和6.97 MPa?m~(1/2)。在1 770℃以下时,陶瓷样品中主晶相为长柱状的β-Si3N4,晶粒彼此间结合紧密,陶瓷气孔率较低。温度继续升高,含铁相和氮化硅发生反应,气孔率增大,抗弯强度和断裂韧性开始下降。如果进一步提高硅铁的氮化率,采用游离硅低、铁含量低及纯度较高的氮化硅铁粉末制备氮化硅铁陶瓷,材料的性能有望得到进一步的提高。
[Abstract]:Si-Fe _ 3N _ 4 multiphase ceramics were prepared by atmospheric sintering with Fe _ 3N _ 4 as raw material and Al _ 2O _ 3 Y_2O_3 as sintering assistant. The phase composition and microstructure of the samples were characterized by X-ray diffraction and scanning electron microscopy. The effects of sintering temperature on the composition, microstructure and mechanical properties of ferrosilicon nitride multiphase ceramics were studied. The results show that the sintering temperature has a significant effect on the microstructure and mechanical properties of ferrosilicon nitride ceramics. With the increase of sintering temperature, the density, flexural strength and fracture toughness of the samples first increased and then decreased to the maximum at 1,770 鈩，

本文编号：1973768