Friction and wear of cast aluminium alloy with laser modified surface layer

The improvement in tribological characteristics of sliding pairs of the piston - cylinder category is mainly associated with aluminium alloys. These materials are subjected to various processes, which modify their behaviour under sliding friction conditions, e.g. wear resistance. The results have been shown in successful application of aluminium alloy pistons in aluminium cylinder liners in piston engines and similar appliances. In the paper the results are presented of tribological research on AlSilSMglCuNi aluminium alloy specimens with surface layer laser modified in cryogenic conditions. The work was carried out at the Mechanical Engineering Faculty of the Gdańsk University of Technology. Eight different sets of specimens were made with different combinations of laser power and scanning velocity. The counter specimens were made of cast iron 300 (PN) equivalent to GG30 (DIN). The tribological research was carried out on TPZ-1 tribometer, described in earlier papers (e. g. Journal of KONES '02), in a flat - on -flat contact lubricated with motor oil and under reciprocating sliding conditions. Real- time friction and overall wear (both specimens together) characteristics have been established. After each hour of the test run the profile was measured of the wear scar on the counter specimen. Such procedure allowed calculating the wear of each specimen separately. The results obtained indicate clear differences among materials modified in different conditions and a general wear resistance improvement in comparison with the unmodified material.