Producing abrasion resistant layers by high energy irradiation and precision mechanical working - to increase fatigue life of engines without labour intensive and environmentally damaging methods

摘要

A process is described for creating an abrasion resistant layer on a light metal alloy combustion engine cylinder bearing surface (CBS) by use of high energy irradiation followed by precision mechanical working. In this method, the irradiating beam (laser, electron) is focussed on the rotating CBS thus treating all of it and causing local melting, defined phase transformations (solid-liq.-solid), homogenisation, redn. of grain size, and hardening to a depth of up to 2mm. After the treatment the cylinder is coupled with a piston which is surface coated with Ni (or Fe) + SiC (or Al2O3). USE/ADVANTAGE - Increases the fatigue life of a CBS without the need for costly multi-polishing steps nor electrochemical methods involving ecologically damaging materials, effective and economic.