Hardened and Toughened Silicon Carbide Composite

"A program is proposed to develop a low-cost silicon carbide-based multiphase composite with high hardness and high fracture toughness using a powder-based processing. High hardness is achieved through composition design and high fracture toughness isaccomplished by microstructure tailoring. The reinforcing phases will be identified and selected, based on hardness, thermal expansion coefficient, compatibility with silicon carbide, melting point, density and stiffness. Silicon carbide polytypes andsintering aid families will be studied to achieve high hardness and high fracture toughness. Taguchi partial factorial approach will be employed to examine the composition and processing parameters. Standard ceramic processing will be used to fabricate100 mm X 100 mm X 7 mm tiles for charactrization, and a quick screening test will be developed for the fracture toughness and hardness measurements. A preliminary database will be established for use in designing a Phase II program to scale up andoptimize the materials and manufacturing processes for the hardened and toughened silicon carbide composite.The program is based on Ceradyne's extensive experience in material development. With the strong background in ceramic manufacturing and marketing, Ceradyne will commercialize the hardened/toughened silicon carbide composite for advanced armor, industrialwear and electronic applications. Silicon carbide has been considered as the most appro