title: The influence of micro-scale dimples and nano-sized grains on the fretting characteristics generated by laser pulses.
abstract: The tribological characteristics of micro-scale dimpled Cu-based alloy specimen generated using a laser surface texturing (LST) were assessed and compared with that of the untextured specimen. The objective of this study is to improve the tribological characteristics of internal combustion engine (ICE) bearings and bushings made of Cu-based alloy by generating micro-scale dimples using an LST. Fretting wear tests were performed by sliding a hardened SAE52100 steel ball against the untextured and LSTed specimens at a normal load of 5 N under oil-lubricated conditions. The friction force and relative movement between the specimens were measured simultaneously during the fretting tests. The test results showed that the LSTed specimens showed a reduction in friction coefficient and an enhancement in fretting wear resistance compared to that of the untextured specimen. The friction coefficient and fretting wear volume increased with increasing frequency for both untextured and LSTed specimens. The improved tribological properties of the LSTed specimen may be attributed to the micro-scale dimples, refined grain size and high lattice strain. In addition, a model for the nanocrystallization mechanism of the LSTed specimen was proposed.
authors.affiliation: Department of Mechanical Engineering, Tokyo University of Science, Tokyo 102-0073, Japan.
authors.forename: Auezhan
authors.initials: A
authors.lastname: Amanov
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Watabe
authors.forename: Shinya
authors.initials: S
authors.lastname: Sasaki