Journal of Inorganic Materials ›› 2017, Vol. 32 ›› Issue (12): 1275-1279.doi: 10.15541/jim20170056

• Orginal Article • Previous Articles     Next Articles

Rare Earth Oxides on Property of Pressureless Sintered Si3N4 Ceramics

Yu-Sen DUAN1,2(), Jing-Xian ZHANG1(), Xiao-Guang LI1, Ming-Ming HUANG1,2, Ying SHI2, Jian-Jun XIE2, Dong-Liang JIANG1   

  1. 1. State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
    2. School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
  • Received:2017-01-24 Revised:2017-04-28 Online:2017-12-20 Published:2017-11-21
  • Supported by:
    National Natural Science Foundation of China (51572277);Ministry of Science and Technology of China (2016YFB0700300)

Abstract:

High thermal conductivity Si3N4 ceramic is a prospective substrate material for high-power electronic devices. In this paper, pressureless and liquid-phase sintering was proposed using Re2O3 (Re=Sm, Er, Lu) - TiO2 as sintering additives to effectively reduce the cost for applications. Effect of the additive type and content on microstructure, mechanical properties and thermal conductivity of the ceramic were investigated. Results showed that the relative density, thermal conductivity and grain size of Si3N4 decrease gradually with the increase of Re ionic (Re3+) radius. With addition of Sm2O3, the highest density can only reach 3.14 g/cm3, while the fracture toughness about 5.76 MPa•m1/2 can be obtained when 8wt% Sm2O3-TiO2 is used. With 12wt% Lu2O3-TiO2 as sintering aid, Si3N4 ceramics show high density of 3.28 g/cm3 as well as high fracture toughness, while the thermal conductivity is only 42 W/(m∙K) due to the presence of large amount of second phase. Thermal conductivity of Si3N4 reaches 51.8 W/(m∙K) with the addition of 8wt% Er2O3-TiO2, which can meet the requirement for substrate materials for power electronic device.

Key words: rare earth oxide, silicon nitride, thermal conductivity, pressureless sintering

CLC Number: 

  • TQ174