Graphite has been used in the friction materials for automobile brakes as a solid lubricant which provider wear resistance of friction materials and maintains smoothness on the frictional surfaces of rotors.
In this study, the effects of graphite to frictional characteristics were investigated under conditions similar to those in practical usage by inertia dynamo meter tests.
The effects of the concentration and particle size of graphite in the brakes materials on the friction coefficient and amount of wear were evaluated.

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The behavior of particle beds in the field of vibration was investigated. The particle flow exhibits either convection or stagnation depending on the size of the container, bed height and the size of particles. The convective flow and stagnation conditions were experimentally elucidated in this study. Particles were fed in a cylindrical container which was vibrated vertically. A ratio of cylinder diameter D to particle diameter D_p and that of bed height H to D were employed as parameters for determining the flow behavior. Influences of vibratory intensity, physical properties of particles and particle shape on the packing density were also investigated experimentally and by computer simulations by the distinct element method (DEM). As a result, it was found that, (1) the stagnation becomes dominant for smaller D/D_p or H/D values, and (2) the packing density becomes maximum at the vibratory intensity Γ≈3.0 for equal spheres irrespective of particle properties, particle shape and particle flow. For non-spherical particles, however, the corresponding value becomes lower than that of spherical ones. In the range of Γ=0-3.0, the packing density increases from an initial value to the maximum with increasing Γ, but it remains at the maximum for decreasing Γ.

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A wet classifier with laminar flow was fabricated based on the principle that the settling location of a particle depends on its diameter. The fabricated classifier produced a sharper particle size distribution profiles with respect to diameter than those obtained using conventional classifiers for particles with diameters ranging from 0.5μm to 5μm. In this paper, the major characteristics of the wet cassifier with laminar flow are discussed, theoretical calculations for the design of the system are done, and the calculated results are compared with the experimental results.

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