FAQ on Copper Alloys
Copper alloys are a standard material for many types of bearing applications. You can imagine them to be like a sponge embedded with a hard wear resistant material for wear resistance. While the copper alloy bearing will correct the minor misalignments between the shaft and the journal, the embedded material like Tin, Nickel etc. shall prevent the wear.
Leaded bronze is a traditional alloy for bearings. They offer a combination of lead embedded in a Copper Tin Matrix. Lead can provide temporary lubrication in case of lubrication failure. Also is has the embeddability properties which can work despite minor dust. Also, it can save an expensive shaft from scouring due to presence of abrasive materials. These alloys form bulk of the bearing requirements.
Tin and copper alloy is very popular where high compressive strength is required. They have an exceptionally good life. But they require a hardened shaft. Also, adequate lubrication must be provided. Tin Bronzes are also more expensive than other grades.
Another important class is the Aluminum Bronze. They have very high strength. So they are more suited to high impact applications. But they cannot embed the dirt well. So, they do not have very good bearing properties. They require clean dust free assembly. Also, they require sufficient and consistent lubrication. Also, they can be used only on hardened shaft.
Major requirements of the bronze bearing alloys are compressive strength, fatigue resistance, temperature endurance, corrosion and seizure resistance and resistance to deformity.
For high loading where the possibility of extrusion or other severe deformation exists the most popular choice the Phosphorus Bronze PB1. Where is the load is of impacting nature, Aluminium Bronze Grades perform well.
Virtually all copper alloys have good corrosion resistance. When this characteristic is combined with other properties such as strength, conductivity, machinability etc. they offer a highly useful group of material to work.
For Underground water or gas service all of Tin bronze, Leaded Bronzes and Silicon bronze are acceptable. In many instances, they are the only alloy specified for water or gas systems, since they offer good operating characteristics indefinitely in service.
Tin bronzes have long been a standard alloy for use in sea water. They are used in equipment such as heat exchanger, marine hardware etc. Manganese or Aluminum bronze is used extensively for ship propellers of all sizes. The large size can weigh over 30 Tons.
Lubrication is important for long life of sliding bearings. There are various types of groove options we have.
In some applications you want the groove to be away from sides to avoid loss of lubricant. In other applications you may want to let the oil enter from sides. So the grooves will be made exposed to sides.