The present study investigated friction and wear of polyetheretherketone (PEEK) resin filled with Rice Bran (RB) ceramics particles (PEEK/RBC composite) under water lubricated condition. RB ceramics particles with mean diameter of 3 µm were compounded with PEEK resin. Mass fraction of RB ceramics particles α was 10, 20, 30, and 40 mass%. As a comparison, monolithic PEEK resin and RB ceramics were prepared. Ball on disk friction testing was carried out using an austenitic stainless steel (JIS SUS304) ball with a diameter of 8 mm under water lubricated condition. Sliding velocity ranged from 0.1 m/s to 2.0 m/s, and normal load ranged from 0.98 N to 9.8 N. PEEK/RBC composites (α = 10～40 mass%) showed significantly lower friction coefficient and specific wear rate under a wide range of normal load and sliding velocity conditions as compared with monolithic PEEK and RB ceramics. It was suggested on the basis of sliding surface observation and surface roughness analysis that the low friction was achieved for PEEK/RBC composites due to an increased hydrodynamic lubrication effect compared with monolithic PEEK and RB ceramics.
It is necessary to understand actual phenomena generated at the electric contacts to suggest the design concept for reducing wear of current collectors such as a contact wire and contact strip in an electric railway. However, rotating wear testing method like pin-on-disk which commonly used to evaluate the wear behavior cannot represent the wear modes of the current collector. In this paper newly linear wear testing method is introduced to represent the wear modes and the wear transition conditions between hard-drawn copper contact wire and iron-based sintered alloy contact strip. As the result, we found that the contact temperature which estimated from contact voltage is depend on current and load, and then friction and wear properties at the current collectors under current condition are classified into three types by the maximum contact temperature.