Enhanced Friction and Wear Behaviour of Electrical Contacts Via Bio Inspired Microstructure Control Produced by Laser Interference Metallurgy

摘要

Friction and wear is a decisive part of function and degradation in sliding contacts and other electrical devices. From nature we can learn on the one hand, that small scale periodic (composite) microstructures are beneficial to combine stiffness as well as toughness properties towards superior wear properties. On the other hand we can learn, that small scale periodic topography enables the precise control of friction behaviour and related effects. In this paper a new technology called Laser Interference Metallurgy is introduced which allows a quick but precise structuring of well periodic microstructures and also surface topographies on large areas but in the micro scale. Basically the high power Laser pulse is split into several sub beams which interfere on the surface of the electrical contact. The interference pattern can be controlled between sub μm and some ten μm. Due to its high and locally periodic Laser intensity the microstructure can be completely redesigned in terms of periodic grain structure, phase formation, texture, residual stress but also topography. This results in strong effects of friction and wear, which will be demonstrated in some detail.