Aluminum Alloy Bearings Containing Hard Particles Fitted for Use with Nodular Cast Iron Shaft

High tin and aluminum alloy bearings can seize easily when used with nodular cast iron shafts. The authors have investigated the process of seizure between such nodular cast iron shafts and high tin and aluminum alloy bearings, and found that the seizures are normally caused by a combination of burrs around the graphite at the surface of the nodular cast iron shafts and abrasive aluminum debris adhering to the shaft. In an attempt to remove the burrs and abrasive aluminum debris, the authors dispersed hard particles in the alloy bearings. The new alloy used has a chemical composition of Al Si 3, Sn 10 and Pb 1.5 and, as a result bearings formed from it do not require a lead-based overlay. This arrangement provides much higher seizure resistance than overlayed copper and lead alloy bearings when used with nodular cast iron shafts. The bearings made with this alloy can be used in all engines with nodular cast iron shafts without any problems whatsoever.