The objective of this project is to develop a novel photopolymerization additive manufacturing process for fabricating fiber reinforced silicon carbide (SIC) matrix composite heat exchangers which…

The objective of this project is to develop a novel photopolymerization additive manufacturing process for fabricating fiber reinforced silicon carbide (SIC) matrix composite heat exchangers which will enable technology for nuclear energy applications. The properties that make SIC desirable for these applications include its low activation when subjected to neutron irradiation, its ability to retain strength and stiffness at elevated temperatures along with its outstanding resistance to oxidation, creep deformation and abrasion. Its low coefficient of thermal expansion and its high thermal conductivity make SIC resistant to thermal shock. The relatively low fracture toughness of SIC has been successfully addressed by adding reinforcing fibers and by engineering the fiber/matrix interface, which render tough, damage-tolerant structures that exhibit non-catastrophic, graceful modes of failure to the point that they have replaced metallic components in aircraft engines. The proposed technology utilizes an advanced additive manufacturing machine and method to fabricate complex SIC components and incorporate chopped fibers to enable composite properties. No commercially available production process exists that can fabricate complex SIC components of the scale, cost, performance, and reliability that will ultimately be required for a broad range of heat exchangers operating in harsh environments. Therefore, this project has significant impact both for the energy sector as well as U.S. Advanced manufacturing capabilities overall. The successful development of this technology will help realize significant increases in energy efficiency and safety margins of advanced nuclear power plants as well as enabling high temperature heat for various industrial uses such as seawater desalination or hydrogen production with important reductions in carbon emissions. In addition to nuclear applications, the use of SIC in a heat exchanger application, radiant tube heater inserts, has previously shown a 15-20% improvement in heat loss and energy demands resulting in 2.24 tbtus of savings per year and reduction of 35.6 thousand tons of CO2 for one specific application previously funded by AMO on unreinforced SIC (no fiber). The GE additive ceramic printing technology will provide similar energy savings and improve safety in energy production in areas like fuel cladding and other structural components that require high thermal conductivity and operation temperatures exceeding 1200°C. Other applications could include structural inverters for photovoltaics (SIC is 99% efficient versus SI at 98%), microturbine components and complex SIC kiln furnace furniture.