| Abstract: | A wide range of literature has been published in the period 1950–2000 concerning emerging concepts relating to the action mechanisms of boundary lubrication additives. Some of the details of these additives in terms of chemical nature, surface adsorption, surface film generation, thermal stability, thermodynamics of contact surfaces, and rise in surface temperature, as reported in this literature, are reviewed in the present paper. It has been observed that the chemical constituents of boundary lubrication additives, particularly of organosulphur and organosulphur—phosphorus origin, are very complex in nature and no comprehensive details are readily available. Regarding action mechanisms, different researchers have suggested different mechanisms for different conditions. However, information on the thermodynamics of surfaces and thermal stability of additives is not readily available. Other details, such as the effect of sliding speed, operating load, surface roughness, and material design, are not covered in this paper. Overall, the literature reveals that attempts to correlate additive characteristics with boundary lubrication activity have met with limited success, and efforts aimed at achieving ever‐increasing performance levels are continuing. In this first part, the authors examine the chemical nature of boundary lubrication additives, the surface films produced, and surface temperature. |
