WEAR CHARACTERISTICS OF AS-CAST BINARY ALUMINIUM-SILICON ALLOYS

Binary as-cast aluminium alloys with silicon content varying up to 21% have been slid against hard steel. Wear rates have been measured at various loads and it is shown that, from the point of view of wear and load-carrying capability, a near-eutectic alloy is the optimum. The hypereutectic alloys wear more but not by more than about a factor of 2 compared with the hypoeutectic alloy. It is concluded that the beneficial effect of silicon is to decrease the propensity to seizure. High silicon alloys, however, wear even hard steel counterfaces. Results of particle size analysis are included to show that although silicon modifies the mode of wear of these aluminium alloys, the distribution of particle size appears to be independent of silicon content and load. Iso-wear lines are plotted for various combinations of silicon and load and it is suggested that this form of presentation will be of help to design engineers if carried out on actual components, e.g. plain bearings. © 1979.