2010 年 28 巻 4 号 p. 421-426
Drilling is widely applied in materials processing. Novel drilling methods, including electrical discharge machining, laser drilling, and plasma arc drilling, have emerged in recent years to overcome such problems as tool wear and low efficiency in the drilling of thick plates or difficult-to-machine materials. Plasma arc drilling is an effective method for the drilling of thick plates, and the quality of the drilled holes is also high. However, the drilling performance of the plasma arc drilling method has not yet been fully elucidated. Since drilling performance is an important criterion in practical processing, we conducted a number of experiments to investigate the drilling performance of this method in terms of penetration ability, electrical energy consumption, and material removal rate. The results obtained for the drilling of mild steel plate of 12 mm in thickness were a penetration time of about 0.75 s, a minimum specific energy of about 30 J/mm3, and a maximum material removal rate of about 300 mm3/s.