Improving microstructural homogeneity of flash sintered SiC ceramics

• Main Author: Al-Munawwarah Binte Abdul Latiff
• Other Authors: Gan Chee Lip
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/176092
• Institution: Nanyang Technological University

In this project, flash sintered SiC are produced at a lower temperature in a short period of time. The electric field provides localized heating which leads to densification through field assisted mass transport. This project suggests a suitable current and power limit for maximising relative density of SiC ceramics. The SiC ceramics was first prepared by cold press using hydraulic pressing machine before sintering. The use of SEM-EDX allows further analysis of samples to mitigate oxidation issue. The results gathered demonstrate that with low temperature, high current, low power limit and sintering aid the relative density of SiC can be further improved. The SiC ceramic is also best densified using a dogbone sample where heating is distributed evenly. Based on the results, relative density of 61.2% is achievable by increasing current density limit to approximately 500 mA/mm². The control of heating rate allows the flash sintering to be carried out at constant temperature. To further improve homogeneity in microstructure, the use of sintering aids such as H3BO3 can also be implemented. As suggested in this project, there are several aspects where densification can be further improved. This suggestion may potentially be used in future work of flash sintering of SiC research.