Inexpensive Large Scale Manufacturing of High Specific Modulus and Strength Ceramic Fibers via VSSP

Boron carbide (B4C) ceramic is one of the hardest materials available and, in the form of a fiber composite, it is expected to improve ballistic performance of personal armor and armored vehicles. Due to the nature of its covalent bond, it is very difficult to manufacture full density boron carbide. Commercially, boron carbide is produced by reacting boron oxide (B2O3) and carbon in an electric arc furnace, which results a slush with a composition close to that of B4C. Due to the noncongruent melting of boron carbide, excess carbon is unavoidable via this method. Therefore, commercial B4C is a composite of B4C and graphite as the second phase, which reduces its mechanical properties. Moreover, there is no commercially available boron carbide fiber to addresses the Army"s growing needs in the field of armor. In this proposal, solutions to both of these shortcomings are addressed by investigating the production of high strength boron carbide fiber and to produce a large volume boron carbide fiber using ACI"s patented viscose suspension spinning process (VSSP) at reasonable cost. VSSP has been used to manufacture numerous ceramic fiber chemistries including alumina and silicon carbide. This technique is fast and easily scalable for large volume production.