A quick test on wear of head materials by recording tapes

A test is described that, within minutes, produces wear data on recording head material-tape combinations. A moving tape is pressed with the coated side against a stationary flat polished sample; using either a sphere or a cylinder for loading the tape. A wear scar is formed on the sample that can easily be measured, with a lower limit of 10³μm³. Examples are given for various materiaI-tape combinations, using loads from 0.02 to 2 N and tape speeds between 0.02 and 5 m/s. The short duration of a test allows many repetitions on one sample and thus good statistics. Each tape yields its own "fingerprint" on a sample material, showing characteristic scratches, material transfer and corrosion. Various materials are compared for a given tape and can be ranked for wear resistance. Wear experiments in videorecorders show a similar ranking of materials and tapes, although the wear coefficients deduced from these life time tests are several orders of magnitude lower.