L. Mueller, R. Bucci, Alcoa, Inc., Alcoa Center, PA
Summary: In complex airframe parts/structures, die forgings represent premium products that are tailored to structural applications. With the emphasis on concurrent performance and affordability issues for airframe structures, the materials selection and design communities are embracing the principles of structural unitization. The emergence of a new generation of aluminum die forged products as a structural “solution” to these challenging unitization objectives involves thick section parts, parting line and residual stress controls, and optimization of directional property behavior.
A number of sophisticated analytical tools have become available to airframe designers to ensure that die forged parts are capable of achieving structural, quality, and schedule benefits compared to baseline flat rolled or extruded aluminum products. The full 3D modeling of complex part geometries has reduced the span time for design development, die sinking, and machining operations, while minimizing distortion in final forged and machined parts. NDT and CMM dimensional controls have been integrated early into the die forged design process to ensure that part thickness and residual stresses are fully considered with respect to final machined parts.
The advanced analytical and materials technologies that are being applied to the next generation of aluminum die forgings will be illustrated in terms of several generic airframe parts, along with a timeline exhibiting the benefits of modeling and simulation tools. This presentation will include:
- Comparisons among previous die forged products and improvements with “new” generation forged products
- Comparisons in terms of other thick section wrought products
- Test and validation program underway on 7085 Al die forgings in collaboration between Alcoa and LM Aero
