Study of Positive Feed Drilling Parameters for Optimized Drilling in Stackups of Composite/Metallic Materials 2005-01-3325
Design limits in aerospace are constantly being challenged forcing engineers to look for materials and material combinations that will provide the strength needed, yet meet the lightweight requirements demanded throughout the industry. These material combinations provide demanding and unique challenges to all involved in the development of robust, reliable assembly processes. As advancements are pushed forward in aircraft materials, advancements must also be made in the technologies/methodologies used to drill close tolerance holes in these complex materials. These advancements will be discussed in the following paper.
Common stack-ups of aircraft materials include various combinations of graphite, aluminum, and titanium. Many problems arise when trying to drill the different combinations of these materials due to the extreme differences in physical properties. The primary factors considered in our studies were feed rates, cutter speed, and preferred cutter geometries for each material. In addition, the effects of forced air along with various coolants were studied and analyzed for possible application.