Oxide-bonded silicon carbide and alumina ceramics obtained from template SCS powders

This study explores the synthesis of SiC@Al2O3 and Al2O3@Al2O3 core-shell structured powders using a templateassisted solution combustion synthesis (SCS) method. Employing urea as the sole fuel resulted in well-dispersed aluminum oxide particles on the silicon carbide surface, while mixed fuels led to agglomeration. Subsequent processing using the template SCS method effectively minimized agglomeration and yielded predominantly the delta-Al2O3 phase. Despite not completely preventing silicon carbide oxidation, the core-shell structures significantly enhanced mullite bond formation, leading to reduced porosity and improved mechanical properties. The SCS method also lowered the mullite synthesis temperature to 1335 degrees C. Cold isostatic pressing further increased density and mechanical properties, resulting in microhardness of 5.2 GPa and bending strength of nearly 50 MPa. Template SCS emerges as a promising technique for producing high-density, high-performance ceramics and composite materials at lower temperatures.