Air Atmosphere Sintering and Characterization of Dense Si3N4 Ceramics

Authors : Gülsüm Topateş

Pages : 940-946

Doi:10.35414/akufemubid.1425085

View : 53 | Download : 61

Publication Date : 2024-08-20

Article Type : Research Paper

Abstract :Air atmosphere sintering successfully applied for Si3N4 ceramics at 1550oC by using double crucible set up. Low weight loss values showed that this set up eliminated oxidation risk. Both sintering time and type of starting Si3N4 powder affected final properties of samples. Sintered densities reached to 3.04 and 2.86 g/cm3 at 3 h for Ube and SicoNide sources, respectively. Around 10 wt. % of beta-Si3N4 is existing in SicoNide powder according to XRD analysis. FTIR study also proved the presence of this phase. This directly retards densification owing to lower reactivity of beta-phase compare to alpha. The major phase formed was beta-Si3N4 with minor amount of alpha-Si3N4 and Si2N2O. Large beta grains were also observed by SEM images from both samples sintered at 3 h. Besides density, dielectric constant, hardness and fracture toughness values quite encouraging for possible applications as substrate in circuits and biomedical materials of air sintered Si3N4 ceramics.
Keywords : Si3N4, havada sinterleme, başlangıç tozu, sinterleme süresi, yoğunlaşma