Study cf Laminated SiC Composites Through Aqueous Tape Casting and Lamination Process

摘要

Many factors for aqueous tape casting process, including the surface properties and surface treatment of SiC powders as well as the dispersant, binder, plasticizer and pH value etc. were studied. On the basis of these studies, multi-layered SiC samples were prepared by stacking the as-cast tapes in the absence and presence of interfacial layers followed by hot pressing in Ar atmosphere. SiC samples without weak interface exhibited improved mechanical properties in comparison with that of bulk ones; while the mechanical properties of SiC samples with weak interface could be optimized by adjusting the thickness and components of the interface, for samples with the interface thickness adjusted as 10 μm and interface component as 50vol%SiC + 50vol%C, the optimal strength, toughness and work of fracture were 580MPa, 10.8 MPa·m~(1/2) and 4282J/m~2 respectively. The failure of these laminates was characterized by a stepped stress-strain response; optical photographs showed that laminated composites exhibit graceful failure and improved fracture resistance behavior.