One Shot Dry Drilling Hole Quality Analysis on Titanium Stacks with ADE Machine 2015-01-2500
The drilling of multi layers composite stacks remains a common process in aerospace industry. Research of productive solutions such as one shot and dry drilling operations to avoid reaming and lubrication are contemplated by aerospace customers on titanium multi layers composite applications. Those solutions permit to reduce the number of finishing operation and drilling time.
Special ADEs (Advanced Drilling Equipment) machines are used to drill aircraft components in limited access areas. Parameters such as cutters, ADE machines type, rigidity clamping, cutting conditions, speed, feed, chip fragmentation and extraction are related and influence the holes quality. Titanium (TA6V) thickness and cutting configuration influence the cutter wear development.
In this work, ADE and specific cutter geometries developed by Apex are used for the one shot dry drilling of titanium. Carbide cutters have been chosen for their resistance to the heat developed by titanium drill. Cutter geometries were evaluated to answer the following quality requirements: diameter accuracy, surface finishing roughness, burrs tolerance. And be according to the manufacturing cost requirement.
For those tests the following parameters have been fixed: ADE machine, experimental configuration (jig, clamping), titanium thickness. Tests have been performed with different feed and peck parameters to choose the optimal cutting parameters.
Coated tungsten carbide drillers were used. Thrust force and torque were analyzed. Chips morphology and cutting wear development was characterized in function to the holes accuracy requirements.