The Effect of Metallic and Oxide Additives on Spark Plasma Sintering and Properties of Silicon Carbide Components
نویسندگان
1 BSc, Department of Ceramic, Materials and Energy Research Center, Karaj, Iran.
2 MSc, Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran.
3 PhD, Department of Ceramic, Materials and Energy Research Center, Karaj, Iran.
4 MSc, Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran, Iran.
5 MSc, Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran, Iran.
doi
10.30501/acp.2025.526982.1177چکیده
This study investigates the influence of metallic (Al, Ti + H3BO3) and oxide (Al2O3–Y2O3 and Al2O3–Y2O3–MgO–CaO) sintering aids on the densification behavior and mechanical properties of silicon carbide (SiC) consolidated by spark plasma sintering (SPS). The primary objective was to reduce the inherently high sintering temperature of SiC while maintaining or improving its mechanical performance. Experimental results demonstrate that appropriate additives significantly lower the sintering onset (as low as 1274 °C for SiC 5Al) and enable high final densities (relative densities >98%, e.g., 98.4% for SiC 3Al2O3 2Y2O3) at overall sintering temperatures below 2000 °C. Among the formulations tested, SiC 10Al achieved a flexural strength of 417 MPa (97.2% relative density), whereas SiC 3Al2O3 2Y2O3 exhibited a Vickers hardness of 29.6 GPa (98.4% relative density). Microstructural observations and phase analysis suggest that liquid-phase formation and additive–matrix interactions govern the observed densification and mechanical trends. These findings indicate that SPS combined with selected metallic or alumina–yttria-based additives represents an effective and industrially scalable route for fabricating dense, high-performance SiC components suitable for demanding applications in the energy, electronics, and automotive industries, as well as in wear-resistant tooling.
