Mechanical characteristics of electrotechnical materials of the system Si3N4-SiC

Conclusions With selected optimal technology of producing materials Si₃N₄,-SiC, their mechanical characteristics may change within fairly broad limits, and they are determined primarily by the composition of the initial charge. Material with optimal composition has a bending strength of 500 MPa and a critical stress intensity factor 6.8 MN/m^3/2.To obtain ceramics with high values of _b and K_1c, it is expedient to use finely disperse highly active silicon carbide (10–30 volume%), and also oxide-free-activators for hot pressing.Increasing the grain size of the conducting phase SiC to 120 m and the amount of activating additive leads to reduced _b of the materials, however, the overall level of strength remains fairly high (>200 MPa).Translated from Poroshkovaya Metallurgiya, No. 1(313), pp. 57–61, January, 1989.