Preparation and Properties of Fibrous Monolithic Ceramics by In-Situ Synthesizing

摘要

Preparation process for fibrous monolithic ceramics by in-situ synthesizing is a simple and cheap way to make ceramics with high performance. In this paper, the process of in-situ synthesizing Si_3N_4 fibrous monolithic ceramics and the main factors which affect properties of the material were investigated in detail. It is found that the reinforcing effect comes from the synergism of the toughening in two different scales. One is the effect of the special fibrous monolithic structure formed by the weak interfaces between fibrous cells. The other is the oriented growth of grains or oriented distribution of whiskers in the fibrous cells. The results show that the fractural toughness of the fibrous monolithic ceramics can reach 23.95 MPa·m~(1/2) at room temperature, and the work of fracture is over 4000 J/m~2.