Processing of Threads on a Magnesium Alloy Using a Special Process

Abstract

Tapping is a complex process largely applied on metal cutting industry. The tapping process can be carried out using cutting or forming tools. This work presents a study of the form tapping process using a tool without cutting edge and helix angle and with external diameter much smaller than the final thread. The experimental tests were carried out with three forming speeds and three helical feed rates to produce M12 threads into the AM60 Magnesium alloy. The results showed that these specfic forming taps provided internal threads with good thread shapes and finishing forms that were as good as the traditional forming tap, which uses tools with the same final thread hole diameter. In addition, the increase of helical feed rate decreases the torque and thrust force, but the differences were greater in torque than in thrust force. The greatest decrease of torque occurred for the lowest forming speed, and the lowest decrease of torque occurred for the highest forming speed. Moreover, the thrust force and torque recorded in the experimental tests were lesser than in traditional form tapping for the same thread area, at least for the magnesiun alloy used.