Rapid Consolidation of Near Net Shape Titanium Alloy Composites for Helicopter Turbines

The extraordinary potential of high-temperature composite materials to meet the engineering design challenges presented by advanced turbine engines is well known. Implementation has been seriously impeded by high cost and fabrication difficulties. Recently, continuous microcomposite monofilaments were produced by physical vapor deposition (PVD) methods to provide an improved alternative to drum-wound foil/fiber or plasma-sprayed monotapes. Such metal matrix composite (MMC) precursors are highly uniform and reproducible. Moreover, the local fiber volume fraction is precisely that desired in the consolidated macrocomposite structure, making the precursor ideal for a precision fiber placement and consolidation scheme. In the proposed work, a unit consolidation process will be modeled and developed using laser energy to effect consolidation of continuous SiC/Ti PVD MMC precursor wires. Feasibility of the approach will be demonstrated in Phase I by fabricating representative cylindrical test specimens. Phase II will explore the dimensions of the processing window, relying on parametric studies to model the consolidation response surface and produce a high-quality full scale demonstration article. The Phase II focus will be on design and development of a commercially viable manufacturing process for components having complex geometry. BENEFITS: Next-generation commercial aircraft turbine engine components will benefit greatly from possible weight savings of more than 50%, compared to currently used superalloys. However truly staggering economies will come from power plants using large land turbines, for which 5% more efficiency can result from a 100¿F increase in operating temperature.