Friction Drilling of Cast Metals
This study investigates the friction drilling process, a nontraditional hole-making technique, for cast metals. In friction drilling, a rotating conical tool is applied to penetrate work-material and create a bushing in a single step without generating chip. The cast aluminum and magnesium alloys, two materials studied, are brittle compared to the ductile metal workpiece material used in previous friction drilling research. The technical challenge is to generate a cylindrical shaped bushing without significant radial fracture or petal formation. Two ideas of pre-heating the workpiece and high speed friction drilling are proposed. Effects of workpiece temperature, spindle speed, and feed rate on experimentally measured thrust force, torque, and bushing shape were analyzed. The thrust force and torque decreased and the bushing shape was improved with increased workpiece temperature. Varying spindle speed shows mixed results in bushing formation of two different work-materials. The energy, average power, and peak power required for friction drilling were calculated and analyzed to demonstrate quantitatively the benefits of workpiece pre-heating and high spindle speed in friction drilling.
F. S. Miller et al., "Friction Drilling of Cast Metals," International Journal of Machine Tools and Manufacture, Elsevier, Oct 2006.
The definitive version is available at http://dx.doi.org/10.1016/j.ijmachtools.2005.09.003
Materials Science and Engineering
Keywords and Phrases
Friction; Drilling; Cast Metals; Chipless Hole Making
Article - Journal
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