Mechanical Spectroscopy of Oil Films on Metallic and Neutral Substrates

Characteristic low-temperature mechanical loss peaks are reported in cold-rolled steel sheets. Similar mechanical loss peaks are observed in both metallic and paper substrates covered with thin oil films. The surface induced origin of these peaks is elucidated through direct comparison of mechanical loss peaks observed in the as-received, cold-rolled samples with loss peaks observed in metallic and paper substrates covered with thin films of the arachis oils. In all of these instances, similar low-temperature mechanical loss peaks are observed in the temperature range from 180 K up to 300 K in both low-frequency resonant and low-frequency sub-resonant mechanical spectrometers. It is concluded that low-temperature mechanical loss peaks are generated by surface induced effects that arise from the oil film itself.