Tool wear reduction through an externally applied electric current

It was shown in a previous investigation that when an electric current is passed between two sliding surfaces in the presence of engine oils, the wear characteristics of two surfaces could be altered significantly, but not friction. The wear on the cathode surface is decreased while the wear on the anode surface increased. The difference in wear rate of surfaces with and without current is attributed to the modification of the elemental composition of surface films. In this investigation, the concept was extended to a machining operation where it is desirable to reduce wear of the cutting tool while increasing metal removal. Two types of experiments were conducted: (a) ball-on-disk test and (b) face milling test. It was observed in ball-on-disk tests that in the presence of a metalworking fluid, the wear of the anode surface decreased significantly while the wear of the cathode surface increased slightly. Similar observations were made in face milling tests where the milling insert wear was reduced when it was the anode and increased when the insert was the cathode. In addition to wear, vibration during milling was also reduced when the insert was the anode.