Torsional Vibration Assisted Drilling (TVAD) process using a Magnetostrictive torsional Transducer

In this paper, a vibrational drilling tool using a magnetostrictive torsional transducer is designed and fabricated. The torsional transducer is a hollow cylinder. which is made up of ‘2V Permendur’. Passing an alternating current through the material creates a variable circular magnetic field a11d exciting a co-axial coil with a direct current, generates a constant axial field in the material. According to Weidman effect, the magnetic domains of the material rotate helically in the direction of the exlemal field and cause a shear strain in the material. To utilize the maximum torque and amplitude of the transducer, as well as to maintain the transducer s resonance conditions, a wave transmitter is designed to connect the transducer to a drill bit. The dimensions of the vibrating tool are calculated theoretically, and verified by the finite element software of COMSOL. Friction couplings are designed to connect the transducer, wave transmitter, and the drill bit. This torsional drilling tool is used for drilling of aluminum work pieces. The tests show that torsional vibrations reduce the required drilling torque by 60% in comparison to conventional drilling. In addition. usage of the torsional vibrations has the effect of the chip fracturing. improving the accuracy of the hole size by 55.4%, and reducing the drilling surface roughness by percent of 25.3% in comparison to conventional drilling.

کلیدواژه ها:

Magnetostricrive transducer ، Pennendur ، some waves ، torsional vibration ،