The Pullform Process

Bonded hollow blade fan are needed for future gas turbine engines. Currently thin ribbed stiffened pre-bond blade halves are made through a process which generates excessive waste of material and requires much machining. This proposal developes the PULLFORM process, a method for forgoing these components to near net shape. PULLFORM localizes high pressure while limiting tool stress. The tooling applies this localized pressure sequentially over the length of the part. The goal if to forge titanium materials above 1300F. In Phase I we made the PULLFORM process for both Aluminum and Titanium blades and forge a minimum of 10 Aluminum subscale parts to verify the modeling. We also collect and analyze data which enables quantifying the anticipated cost and efficiency benefits of the PULLFORM process in comparison to current technology. The results of these two activities enable meeting milestones which lead to determining the process parameter requirements, equipment and estimated costs for a full scale prototype for forging titanium half blades at high temperatures in Phase II. Anticipated Benefits: The development of affordable commercial and advanced military fighter engine hollow fan blades is a current priority for engine manufacturers. The potential of the project is demonstrated by the no cost participation of our probable partner, Pratt & Whitney, in this project.