52 Bronze
It was not until somewhere around 5000 BC that copper was mixed with tin to produce a much harder metals called bronze. The discovery of bronze was such an important time to historians and archeologists that it has come to be known as the Bronze Age.
Video
Watch this 18:42 video Mining This Rock Unlocks the Bronze Age by How To Make Everything, Juen 20, 2019.
Bronze remains a material in common use today. Alloys other than tin have since been added to copper to produce substantially different properties. The most common alloys are phosphorus, aluminum, manganese, silicon, nickel, lead, and iron. The first four alloys play the main role in bronze metallurgy therefore bronze has been divided into four groups:
- Phosphor Bronze,
- Aluminum Bronze,
- Manganese Bronze, and
- Silicon Bronze.
Following are four bronze alloys, one from each group. Note that the machinability indications are comparing bronze to bronze.
C64200
- Primary alloy aluminum
- Machinability good
- Weldability fair for all methods except oxy
- Applications valve and pump components, marine equipment
- Comments a free machining and anti galling copper alloy
C67500
- Primary alloy manganese
- Machinability fair, galls easily
- Weldability best to solder or braze
- Applications valve and pump parts, bearings, heavy duty mechanical components
- Comments hot forgeable alloy combining high strength and good corrosion resistance
C67500
- Primary alloy phosphor
- Machinability very good
- Weldability best to solder or braze
- Applications bearing and cam followers
- Comments very good wear resistance
C65500
- Primary alloy silicon
- Machinability poor, galls easily
- Weldability best to braze while other methods are good
- Applications valve guides, valve stems, fasteners, pole line hardware, and marine fittings.
- Comments moderate strength, good corrosion resistance, similar to C64200 in properties and applications.
Derived from The Virtual Machine Shop (2011) http://jjjtrain.com/3engineering/7eng_metalsl_hist/eng_metal_hist_07.html via the WayBack Machine internet archive 16 February 2024.