NSF Award
9901850
This Small Business Innovation Research (SBIR) Phase II project will combine particulate reinforced titanium metal matrix composites (PRMMC) with an innovative forming process to produce aircraft engine ducting. Metal matrix composites, designed for stiffness at elevated temperatures are extremely difficult to form into useful shapes. A unique phenomenon, internal stress superplasticity, circumvents the forming problem by producing uniform viscous flow in titanium PRMMC's with only a light applied stress during repeated thermal cycling through the allotropic phase transformation temperature range. Phase I produced uniaxial stretching of nearly 300%. Phase II process development will transform PRMMC composite into useful axisymmetric tubular shapes, such as used for ducting on commercial aircraft engines, by utilizing advanced infrared heating (rapid thermal cycling at 1-4 cycles per minute) to "blow mold" a preform tube into final geometry in 30 minutes of superplastic forming. The project will scale up uniaxial results to multiaxial sheet bulging and tube bulging processes on a 4 inch by 12 inch scale. The final component will replicate a duct component from the aerospace engine industry. <br/> Commercial applications include components such as aircraft engine ducting, heat exchanger tubing, offshore pipe fittings, and valves. Complex shaped components, particularly those axisymmetric in nature which require high strength and corrosion resistance, will benefit from this technology. It is anticipated that these applications will span many market areas including aerospace, industrial, and consumer markets.
