Friction and abrasion of hard solids at high sliding speeds

Source abstract

Abstract An investigation has been made of the friction and wear of hard solids such as sapphire (Al2O3), rutile (TiO2), TiC, SiC, diamond and fused silica (SiO2) sliding on metal surfaces at very high speed (700 m/s). It is shown that hard solids can undergo extensive wear when rubbed against metals of much lower hardness. There is evidence that this apparently anomalous effect is due partly to the abrading effect of small particles of the harder material which becomes dislodged and dragged across the surfaces. This disintegration may be caused by therm al shock due to the high temperature gradients produced, while in some cases chemical reactions or solid solutions may lead to strong adhesion between the metal and the non-metal. With diamond there is supporting evidence that the abrasion process is accompanied by a thermal transformation into amorphous carbon.