Thermal Conductivity and Mechanical Property of Si3N4 Ceramics Sintered with CeF3/LaF3 Additives

In this paper, rare-earth fluorides were used as sintering additives instead of rare-earth oxides, the influence of the type and the amount of the fluoride on the thermal conductivity, hardness and strength of Si(3)N(4) ceramics was studied. Results show that the thermal conductivity of a sample sintered with CeF(3) is nearly 10% higher than that of the sample sintered with Ce(2)O(3), while the samples sintered with LaF(3) increases further 15% as comparing with the samples sintered with CeF(3). The strength of the samples changes reversely. These results express that the thermal conductivity of Si(3)N(4) ceramics can be improved by using rare-earth fluoride additives instead of the oxides, and the type of rare-earth fluorides has a significant impact on the properties of Si(3)N(4) ceramics.