Bronze - Wear Resistance and Marine Performance

Metallurgy and industrial bronze grades

The term bronze designates a family of copper-based alloys whose composition varies according to the properties sought. Standard bronze (copper-tin) generally contains 88 to 92% copper and 8 to 12% tin. Other important grades include leaded bronze (lead added to improve machinability and sliding properties), phosphor bronze (phosphorus addition to increase hardness and wear resistance) and aluminum bronze (aluminum added to improve mechanical strength and corrosion resistance).

Aluminum bronze deserves special mention for demanding marine and industrial applications. Its mechanical strength (yield strength of 250 to 500 MPa depending on composition and heat treatment) and superior marine corrosion resistance compared to standard bronze make it a prime material for ship propellers, marine pumps, underwater valves and offshore equipment components.

Bearing and bushing applications

The most classic application of industrial bronze is the fabrication of bearings and bushings. Bronze, particularly leaded bronze or self-lubricating graphite bronze, offers an extremely low coefficient of friction against steel surfaces, the ability to support significant loads and wear resistance that guarantees long service life even under conditions of insufficient lubrication.

Bronze bearings are used in a multitude of applications: centrifugal pump shafts, hydraulic cylinder bearings, press guide bushings, industrial conveyor bearings, crane and hoist components, and agricultural and forestry machinery parts. Their ability to function under limited or water lubrication conditions is particularly valued in environments where continuous lubrication is difficult to maintain.

Marine applications and hydraulic equipment

In the maritime domain, bronze has been used for millennia for components in contact with seawater. Boat propellers, propeller shafts, rudder bearings, mooring bollards, deck fittings and seawater cooling system components are commonly fabricated in bronze, particularly aluminum bronze for high-performance applications.

Industrial hydraulic equipment uses bronze for numerous components: valve bodies, valve seats, cylinder pistons, guide bushings and fittings. Bronze’s resistance to cavitation, an erosion phenomenon caused by the implosion of vapor bubbles in pressurized fluids, is particularly valued in high-velocity flow pumps and valves.

Non-sparking property

One of bronze’s most important properties in certain industrial environments is its non-magnetic and non-sparking nature. In explosion-risk environments (atmospheres containing flammable gases or combustible dusts), the use of bronze tools and components is often required by safety regulations. Oil installations, flammable chemical depots, flour mills and grain silos use bronze components specifically for this safety property.

Machining and fabrication of bronze at ADI Laval

Bronze is generally a pleasant material to machine, with excellent machinability for most grades. Our shop has the equipment necessary to process bronze by cutting, turning (with partners), milling and assembly according to your part specifications. For bearings and bushings, dimensional tolerances and surface finish are critical for proper assembly function, and we pay particular attention to these aspects during fabrication.

Bronze weldability varies by grade. Standard bronze and aluminum bronze can be welded by adapted TIG processes, but bronze welding requires specific expertise due to the alloy’s sensitivity to heat and the risks of segregation and porosity. Our technicians are trained in the specificities of copper alloy welding and can produce quality welded assemblies when the design requires it.