Several methods of large-scale metal additive technologies have been developed over the last several years and have demonstrated impressive material property characteristics and potential for rapid production of large parts. High strength aluminum and titanium forgings sometimes take upwards of one year to procure and there is an urgent need for alternate manufacturing capability of large critical aerospace structural hardware to reduce lead times. The MELD process is a solid-state additive method with the ability to scale to large build volumes. The present research evaluates the MELD process applicability for 7XXX series aluminum and Ti6Al4V components traditionally machined from forged products. 7XXX series aluminum alloys are difficult to print using melt-based wire or powder methods without altering the standard feedstock chemistry. The feedstock for MELD machines is available off the shelf for the alloys being considered in this presentation. This process, known as additive friction stir deposition (AFSD), uses mechanical deformation to metallurgically bond each layer to the previous layer. The process is very fast and large parts with prohibitively long forging lead times can be printed in a matter of days. Both, aluminum and titanium, need to be post print machined for the applications being investigated. Post print heat treatment is required for 7XXX series aluminum.
Currently, all evaluation of titanium has been in the as-printed condition. Microstructure control, mechanical properties, non-destructive evaluation, future data collection, and applications will be covered in this presentation. Unique process capabilities and considerations will be discussed as well as an overview of the advantages and disadvantages of AFSD for forging replacements in the aerospace industry.
Learning Objectives:
- Describe the pros and cons of aerospace structural alloys produced by AFSD for large parts
- Understand the current state and near future of AFSD technology from a material and process development standpoint
