SBIR-STTR Award

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 is accomplished 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 and sintering 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 fabricate 100 mm X 100 mm X 7 mm tiles for characterization, 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 and optimize 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, industrial wear and electronic applications. Silicon carbide has been considered as the most appropriate ceramic component for vehicle armor for military, law enforcement and protective service industry. The hardened and toughened silicon carbide composite could benefit both public and private armored vehicles used for humanitarian demining and unexploded ordnance cleanup. The resulting silicon carbide composite can be used in high temperature and/or corrosive industrial processing applications as a wear-resistant material.

Composition hardening and microstructure toughening are proposed to develop a low cost silicon carbide-based multiphase composite for advanced armor applications. In the Phase I program, different reinforcement particles and volume fraction have been examined. The hardened and toughened silicon carbide has been demonstrated through this composite approach. The material/process optimization and dynamic behavior investigation are proposed in the Phase II program. Silicon carbide phase transformation, composite micromechanics, and chemical stability will be examined to optimize both hardness and fracture toughness simultaneously. The optimized material/process will be selected and characterized under high strain rates. Phenomenology testing, armor ceramic characterization and armor system design will be performed to understand the dynamic properties of the hardened and toughened silicon carbide and to demonstrate the efficiency as the armor ceramic component through an armor system under a specific threat. The program is based on Ceradyne's extensive development, manufacturing and marketing background for both ceramic fabrication and armor system design and assembly. The commercialization of this new material is not only going through Ceradyne's exiting marketing and sales channels for ceramic components as armor and industrial wear parts but is also carrying out as ceramic hard-face in Ceradyne's designed armor systems. The unique business capability at Ceradyne can successfully commercialize the technology. Silicon carbide is the most appropriate ceramic for vehicle armor for military, law enforcement and protective service industry. The hardened and toughened silicon carbide could benefit both public and private armored vehicles used for humanitarian demining and unexploded ordnance cleanup. The resulting silicon carbide can be used in high temperature and corrosive industrial processing applications as a wear-resistant material

Keywords:
silicon carbide, hardness, material optimization, microstructure, armor, toughness, dynamic behavior, impact