Effects of adsorption of ATF additives to wet friction materials on friction performance at the low sliding velocity range

摘要

Measurements of heat of adsorption of succinimide-based dispersant (dispersing agent) used as an ATF additive and two types of phosphate based friction modifier (FM) by wet friction materials were performed. On the basis of obtained results, two kinds of wet friction materials were prepared by admixing activated carbon with high adsorptive power (CF-1) or graphite with low adsorptive power and adding phenol resin, which then was hardened by heating. Also, the above ATF additive was introduced into an additive-free mineral oil used as a base oil to prepare test oils and their friction characteristics (μ-V characteristics) were measured in the range of low speeds of sliding. Obtained results showed that (1) in the case of CF-1 and CF-2, μ-V characteristics changed significantly with the introduction of an ATF additive, and when the concentration of the additive increased from 1 to 5 mass %, the change was not large for CF-1, but for CF-2, the coefficient of frictionμreduced with some exceptions; and (2) a reduction of the coefficient of frictionμwith adding of a DM additive was controlled by the dispersant and at the addition of FM to 1 mass %, its efficiency was higher for CF-1. Consideration of obtained results and the adsorption behavior of ATF additive showed the necessity of new studies directed at the optimization ofμ-V characteristics by determining the efficiency of the adsorption of ATF additive by wet friction materials in an improvement ofμ-V characteristics.