Effect of sintering temperature on microstructure and mechanical properties of highly porous silicon nitride ceramics produced by freeze casting

✍ Scribed by Feng Ye; Jingyi Zhang; Haijiao Zhang; Limeng Liu

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 481 KB
• Volume: 527
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2010.07.038

✦ Synopsis

Highly porous Si 3 N 4 with macroscopically aligned pores were prepared by the unidirectional freeze casting process using liquid N 2 as refrigerant. The increased sintering temperature had no obvious influence on the porosity, but significantly promoted ␣ → ␤-Si 3 N 4 phase transformation and the growth of fibrous ␤-Si 3 N 4 grains, and changed the pore structure. The flexural strength and fracture toughness of the sample sintered at 1900 • C could reach 73 MPa and 1.1 MPam 1/2 , respectively.