Action Mechanism of Load-Carrying Performance of a New Lubricant Additive

A new load-carrying additive belonging to the class of organo-metallic compounds having ligands of 8-hydroxyquinoline has recently been developed. The additive provides excellent lubrication for motor oils under very high load and speed conditions; it also acts as friction modifier.

A study has been made to elucidate the action mechanism of this additive. An approach based on the negative ion concept has been applied. To determine the formation of negative ions of this additive and its ligand, electron attachment mass spectrography was used.

On the basis of the results of mass spectrographic and tribological investigation, a lubrication mechanism of this additive has been proposed. The mechanism provides one explanation of all the friction and wear reduction effects of the additive experienced in practical applications.     

Advanced Friction–Wear Behavior of Organic Brake Pads Using a Newly Developed System

The objective of this study was to investigate the influence of an advanced performance system on the tribological behavior of brake pad material using a specially designed brake pad tester system following standard SAE J-661. The tribological behavior and friction and wear characteristics of the organic brake pad samples were evaluated. During braking tests, the samples, in contact with a cast iron disk, were studied at different disc speeds, temperatures, and braking cycles under a constant pressure. In order to understand the friction and wear behavior, the unworn surfaces, worn surfaces, and wear debris were characterized by means of scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). Furthermore, the surface characteristics and differences in the wear modes of the brake pad samples were examined. Wear debris was permitted to deform the brake pad surfaces, leading to friction layers and enabling the estimation of the friction behavior of the brake pads. The results showed that the best friction–wear behavior was obtained with lower braking cycles at low speeds and temperature. Thus, the newly developed brake pad tester system proved very effective in evaluating the performance of the brake pad samples.