EXPERIMENTAL DETERMINATION OF TRIBOLOGICAL CHARACTERISTICS OF COMPOSITE MATERIALS IN USE FOR PARTS IN ALUMINUM AIR COMPRESSOR (PISTON AND CYLINDER)

Abstract

For reciprocating machines are applicable different materials for the piston skirt and piston rings as well as for cylinder liner. The friction and wear of the piston group is highly dependent by the material and the honing of cylinder liner, the coating characteristics, the piston ring dimensioning and tension. If using aluminum alloys for producing of piston and cylinders in engines and compressors, the results are lower fuel consumption and exhaust emission, firstly because of lower weight and mechanical losses, too. The problems are poor tribological characteristics and lower strength of unprotected aluminum comparing with gray cast iron. In this paper, the tribological properties of ferrous and graphite-based reinforcements were analyzed and compared with aluminum alloy as a base material for cylinder liner and piston skirt in air brake compressor. The ball-on-plate CSM nanotribometer was used to carry out these tests under dry sliding conditions and constant sliding distance, for three different values of sliding speed and normal loads.