Friction surfaces are required for improvement of tribology characteristics. In this study, the friction behavior of high silicon aluminum alloy (AC8A) with surface texture was investigated using a ball (SUJ2)-on-plate reciprocating friction tester. The surfaces of the specimens were processed by the wet blast technique to produce texture. The test slurry was pure water containing angular alumina particles 1.2 μm in diameter. The injection angle was set to 30°and 90°. Surfaces with protruded Si (injection angle of 30°) were shown to have low friction. Especially, surfaces with protrusion height ≥ 0.88μm and protrusion area ≥9.5% were effective in maintaining low friction.

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The authors attempted to improve the tribological characteristics of stainless steel by fine particle peening (FPP) to transfer fine diamond powders onto the treated surfaces. FPP using specially developed diamond/steel hybridized particles induced the transfer of diamond powders followed by their embedding into the substrate. The surfaces modified with diamond exhibited low friction coefficients as well as reduced wear. The reductions in friction and wear were because the wear particles produced from the FPP-surfaces and covered the wear tracks suppressed adhesion between sliding systems. Advantages of FPP using the hybridized particles could be realized because of its ability to create modified surfaces with embedded diamond powder.

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We have developed a precision truing technology using a quartz plate, as a new truing method for CBN electroplated wheels. Quartz-truing can suppress the variation in abrasive grain cutting edge protrusion, forming a mirror-finished surface of the abrasive top flat area, and an increase in the number of active grains was confirmed. Grinding of bearing-steel using a small-diameter CBN electroplated wheel that was quartz-trued obtained a very smooth surface with 11.1 nm Sa and 89.0 nm Sz. We examined the polishing mechanism of the CBN abrasive grains experimentally, with confirmation of boron in the polished powder and detection of NOx gases during polishing. We showed that CBN is decomposed by the increase in heat during polishing.

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