Bronze – a multifarious material

Bronze is a copper-tin-alloy which you can differentiate between wrought alloy and cast alloy. Wrought alloy has a tin constituent up to 8,5%, cast alloy between 9-12%.

To impact the material properties bronze can be combined with alloy components and additives, mostly phosphor and tin for wrought alloys and lead, nickel and iron for cast alloys. Due to the additional additives the bronze alloys are called multicomponent-bronze.

The added tin permits a higher strength and hardness than copper. Rising tin causes decreasing conductance but increasing strength and hardness of the material. Bronze is resistant to corrosion and sea water, wear-resistant and has good floating properties. It has excellent endurance strengths.

Wrought alloys are suitable for hot and cold formability. With a tin constituent up to 8% bronze is applicable for the electrical and mechanical engineering as well as the automotive industry. These alloys are difficult to machine but to weldable without problems. Especially the tungsten-inert gas welding and the resistance welding stand the test. If components are exposed to corrosive elements please notice that the fasteners like riveting and screws are similar-  to avoid contact corrosion.

Bronze cast alloys are among the most noncorrosive copper alloys. With an adherent and dense protective coating it has an excellent durability against several atmospheric effects. With increasing tin the protecting effect increases as well. Various multicomponent-bronzes stand out due to its good floating and fail-safe properties.

Cast alloys are generally better machinable than wrought alloys with comparable composition. Multicomponent-bronzes with a lead content of 2% is excellent machinable and soft-soldering. If the lead content exceeds 2% the bronze is just conditionally weldable. Please notice that excessive heat and welding voltage should be avoid at repair welding. The use of fasteners is comparable to wrought alloy. The application area for bronze cast alloys are i.a. mechanical engineering, automotive industry and shipbuilding but even electrical engineering and the food industry.