SBIR Phase II: Microwave Heating of Reaction-Bonded Silicon Carbide Ceramics

This Small Business Innovation Research (SBIR) Phase II project enables an innovative low cost approach to reaction bonded silicon carbide (RBSC). RBSC is a preferred material for mechanical seals, which are critical, costly components in many major manufacturing lines. The high cost of RBSC limits its use in favor of cheaper, shorter lived materials. A microwave heating process, combined with lower cost raw materials addresses RBSC cost issues. Phase I research identified a process range for producing RBSC with flexural strength above the industry average. The Phase II research will yield reliably high strength RBSC. The key objective for Phase II is optimization of all-carbon preform formation, and microwave infiltration methods, to fabricate prototype mechanical seals for industrial evaluation. The new RBSC will be characterized according to mechanical seal industry approval specifications. Innovative forming processes including 3D printing will be studied for the ability to quickly form complex, custom, near net preforms for infiltration. The anticipated result is a commercially ready, lightweight, high strength RBSC that will be preferred for existing and new applications. The broader impact/commercial potential of this project will include significant cost reductions for wear resistant applications. A low-cost, superior performance mechanical seal will improve efficiency, with fewer costly production shut-downs due to pump failures. RBSC provides a longer overall lifetime than tungsten carbide, graphite, or alumina parts, further reducing life cycle costs. Mechanical seals cost on average $750 per inch of diameter, ranging up to 15" across. This research will enable a 50% reduction in RBSC cost, developing a viable, high performance product, along with market demand. Recent consolidation of major silicon carbide suppliers provides an opening in the market to support a new, independent RBSC source. The RBSC process uses a greener microwave process, with time, energy and greenhouse gas reductions of 50 to 80%. The commercial demonstration of microwave RBSC product will provide a needed boost to encourage other manufacturers to uptake cleaner, efficient microwave processing. The project also supports Science Technology Engineering Mathematics (STEM) education through high school projects and at least four undergraduate engineering co-op students.