Friction and wear of magnetic heads and amorphous metal sliding against magnetic tapes

The friction and wear both of various audio heads and of an amorphous ribbon sliding against various magnetic tapes were studied. The magnetic cores of the audio heads were made of ferrite, Sendust, and an amorphous metal. The magnetic tapes included a γ-Fe2O3tape, a metal particle tape, and an evaporated metal tape. These last two are generally considered to be the ultimate compositions for high density magnetic recording. The ferrite head generally gave the low coefficients of sliding friction in contact with any type of magnetic tape. The amorphous metal head exhibited the greatest wear, despite its considerably higher hardness. The worn surfaces of the various magnetic materials were observed with an scanning electron microscope (SEM). It was concluded that the mechanism of wear by both the γ-Fe2O3tape and the metal particle tape is not entirely due to the abrasive action of the magnetic powder in the tapes, but is also partially due to adhesion. Wear by the evaporated metal tape, however, is caused mainly by adhesion. The surface of an amorphous ribbon rubbed by tapes was examined with the reflection high energy electron diffraction (RHEED) method. The results suggest that the surface was partially crystallized during the running.