Tribological Behavior of Friction Materials Affected by Boehmite Impregnation

Abstract

Focus of this study has been placed on the effect of boehmite impregnation methods at densification on tribological and mechanical behavior of friction materials. Experimental results indicate that open porosity decreases with the numbers of impregnation cycle. Both bulk density and flexural strength increase with the numbers of impregnation cycle. The friction coefficient and the mass loss of the impregnated specimen is shown more stable and lower than that of the green specimen. Morphological observations show that the number of open pores for these materials decreases but they exhibit a denser and smoother morphology as the number of impregnation cycle increases. Furthermore, as the number of densification cycle increase, the friction behavior of impregnated specimens becomes more sensitive to the presentation of γ-Al₂O₃ particles. Therefore, the friction coefficient of specimens becomes higher but more unstable; in the mean time, the mass loss becomes larger.