微細断続切削によって付与したディンプル形状がアルミニウム合金の摩擦特性に及ぼす影響

抄録

Tribological properties of textured surfaces fabricated with an interrupted micro cutting process (tiling^TM) were investigated. An aluminum cast alloy (AC8A) disc was used for the specimen. The proposed texturing process was carried out using a CNC machining center. The surface texture was fabricated with a cutting tool having an asymmetrical geometry. The resulting surface morphology consisted of aligned micro dimples having a diameter of 180-630µm and a depth of 2-40µm, with controlled area fractions varied from 10 to 50% and the top region was finished with polishing. The tribological properties evaluated using a threeball-on-disc-type testing apparatus in lubricated conditions showed that the friction coefficient of the textured surfaces was low and stable from the beginning of the experiment. A dependence of the texture geometry including the dimple size and the area fraction on the friction coefficient was also found. It is concluded that the surface texture consisted of smaller dimples less than 280µm and the area fraction smaller than 20% is preferable to reduction of the friction coefficient.