Nanoscale wear and kinetic friction between atomically smooth surfaces sliding at high speeds

TL;DR

This study investigates nanoscale wear and kinetic friction at high speeds using a hard disk drive interface, revealing unique insights into friction, wear, and material degradation at the nanoscale under high-velocity conditions.

Contribution

It introduces a novel experimental setup for studying high-speed nanoscale friction and wear, providing new data on friction coefficients and shear strength at the head-disk interface.

Findings

Friction coefficient and shear strength measured at high sliding speeds.

High-speed sliding causes measurable wear and degradation.

Experimental setup enables systematic nanoscale friction studies.

Abstract

The kinetic friction and wear at high sliding speeds is investigated using the head-disk interface of hard disk drives, wherein, the head and the disk are less than 10 nm apart and move at sliding speeds of 5-10 m/s relative to each other. While the spacing between the sliding surfaces is of the same order of magnitude as various AFM based fundamental studies on friction, the sliding speed is nearly six orders of magnitude larger, allowing a unique set-up for a systematic study of nanoscale wear at high sliding speeds. In a hard disk drive, the physical contact between the head and the disk leads to friction, wear and degradation of the head overcoat material (typically diamond like carbon). In this work, strain gauge based friction measurements are performed; the friction coefficient as well as the adhering shear strength at the head-disk interface are extracted; and an experimental set-up for studying friction between high speed sliding surfaces is exemplified.