Effect of MgF2 addition on mechanical properties and thermal conductivity of silicon nitride ceramics |
| |
| Affiliation: | 1. School of Materials Science and Engineering, Harbin Institution of Technology, Harbin, 150001, China;2. Department of Physics, Harbin Institute of Technology, Harbin, 150001, China;3. Institute of Telecommunication Satellite, China Academy of Space Technology, Beijing, 10094, China;1. Key Laboratory for Liquid-solid Structural Evolution & Processing of Materials of Ministry of Education School, Shandong University, Jinan, 250061, PR China;2. Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Jinan, 250061, PR China;3. Key Laboratory of Colloid and Interface Chemistry, School of Chemistry and Chemical Engineering, Ministry of Education, Shandong University, Jinan, 250100, PR China;1. Nanjing Electronic Devices Institute, Nanjing, 210016, China;2. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China;3. University of Chinese Academy of Sciences, Beijing, 100049, China;4. Shanghai Radio Equipment Research Institute, Shanghai, 200090, China |
| |
| Abstract: | Dense silicon nitride (Si3N4) ceramics were prepared using Y2O3 and MgF2 as sintering aids by spark plasma sintering (SPS) at 1650 °C for 5 min and post-sintering annealing at 1900 °C for 4 h. Effects of MgF2 contents on densification, phase transformation, microstructure, mechanical properties, and thermal conductivity of the Si3N4 ceramics before and after heat treatment were investigated. Results indicated that the initial temperature of liquid phase was effectively decreased, whereas phase transformation was improved as increasing the content of MgF2. For optimized mechanical properties and thermal conductivity of Si3N4, optimum value for MgF2 content existed. Sample with 3 mol.% Y2O3 and 2 mol.% MgF2 obtained optimum flexural strength, fracture toughness and thermal conductivity (857 MPa, 7.4 MPa m1/2 and 76 W m−1 K−1, respectively). It was observed that excessive MgF2 reduced the performance of the ceramic, which was caused by the presence of excessive volatiles. |
| |
| Keywords: | Fluoride Thermal conductivity Silicon nitride Spark plasma sintering |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
