Increase of the Coefficient of Static Friction Using Turn-milling with an Inclined Milling Spindle

There is a strong need for surfaces with a high coefficient of static friction to meet the demands for increasing performance and lightweight construction strategies, especially regarding friction-locked connections. An auspicious turn-milling process used to generate protruding surface structures which lead to a high coefficient of static friction is investigated. The influence of the corner geometry on the surface structure is examined by machining end faces of specimens of the steel 42CrMo4+QT (1.7225). Experimental tests for the identification of the coefficient of static friction show a significant increase up to 275% (μ0.1° = 0.55) for turn-milled surfaces in comparison to unstructured specimens (μ0.1 ≈ 0.2).