Glossary

Bronze is a metal alloy primarily composed of copper (Cu) and tin (Sn), often containing small amounts of other elements such as aluminum, phosphorus, manganese, or silicon to enhance specific properties. It is one of the oldest and most significant alloys in human history, marking the technological leap known as the Bronze Age (around 3300–1200 BCE).

Bronze was the first alloy intentionally created by humans, and it quickly replaced stone and pure copper tools because of its superior hardness, strength, and durability. Adding tin to copper changes the alloy’s crystal structure, making it stronger, less brittle, and more resistant to corrosion.

In appearance, bronze has a reddish-brown to golden color, which can darken or develop a greenish patina (a layer of copper carbonate) over time due to oxidation. This patina actually protects the metal from further corrosion, making bronze extremely durable — a reason why ancient bronze artifacts, statues, and coins often survive for millennia.

Bronze’s properties can vary depending on composition:

- Phosphor bronze (copper + tin + phosphorus) is tough, wear-resistant, and used for springs, bushings, and bearings.

- Aluminum bronze (copper + aluminum) is stronger and highly corrosion-resistant, often used in marine hardware and fasteners.

- Silicon bronze (copper + silicon) has excellent corrosion resistance and weldability, used in architecture, sculptures, and boat fittings.

Because of its low friction and non-sparking characteristics, bronze is commonly used in bearings, gears, bushings, and tools for environments where sparks could ignite gases or vapors. Its acoustic properties also make it ideal for musical instruments such as bells, cymbals, and strings for pianos and guitars.

In art and architecture, bronze has long been valued for its workability and beautiful aging, used in statues, memorials, and decorative fittings. When molten, it fills molds cleanly, capturing fine detail, which is why bronze casting remains the preferred method for sculptures.