Discussion: “Specific Heat of Tribological Wear Debris Materialâ€‌ (Maciؤ…g, M., 2015, ASME J. Tribol., 137(3), p. 031601)

Abstract

The thermal load acting on the MAZ is the share of the particular solid from the work of the friction force. The dissipated heat to the bulk of either rubbing solids has two contributions. The first is the heat conducted toward the bulk, whereas the second is the heat carried out by the detached wear particles. Wear particles separate from the surface bearing the thermophysical properties of the interface at the moment of detachment. Once detached, their thermophysical properties continue to evolve through a different path than that of the MAZ. In this sense, detached wear particles do not continue to contribute to the thermodynamic of a rubbing solid other than representing the surroundings to a system [1,2]. Seeking the heat capacity of the separated debris postmortem, therefore, is misleading and masks the actual energetics of wear particle generation process itself.