Enabling Materials Processing Technology for Low-Cost Fabrication of Integral Bladed Rotors (IBR)

IBR manufacturing is an essential part of gas turbine fabrication for modern fighter aircraft, yet remains a significant cost component. Stringent dimensional (distortional) tolerance and surface finish requirements necessitate the need for precision manufacturing. Currently, F-135 and F-119 IBRs are initially forged from bar stock titanium or nickel alloy, ultrasonically inspected, rough machined and subsequently electro-chemically machined (ECM). The ECM process is chosen since it allows machining of complex features. However, the process itself is expensive due to significant amounts of material removal and surface finish requirements, driving per-part processing times to 40-50 hours or more. In Phase I of this project we will demonstrate innovative forging and high speed machining (HSM) technologies the Air Force needs which enable affordable fabrication of IBRs resulting in a 35-50% cost reduction. Teaming with Pratt and Whitney and Ladish, and our experience in successfully implementing innovative metal manufacturing techniques ensures the success of our program. We will assess the feasibility of our innovative and proven physics-based predictive modeling approach to ultimately combine near-net shape forging and HSM technologies with fine-grained materials and low noise titanium to reduce raw material consumption, cycle times, and reduce or eliminate ECM.