What is the percentage composition of zinc and copper in brass alloy respectively?

30% zinc and 70% copper

The correct answer is option 2. 30% zinc and 70% copper.

Let us delve into the world of brass and explore the concept of alloy composition.

Brass:

Brass is a versatile metal alloy, meaning it's a mixture of two or more metals. The primary components of brass are:

Copper (Cu): This metal provides the base for the alloy, offering good electrical conductivity, malleability (ability to be shaped), and ductility (ability to be drawn into wires).

Zinc (Zn): When added to copper, zinc lowers the melting point of the mixture, making it easier to cast and shape brass. Additionally, zinc enhances the strength and machinability of the alloy.

Percentage Composition:

The ratio of copper and zinc in brass can vary depending on the desired properties of the final product. Here's a breakdown of two common types:

C260 Brass (Commercial Brass): This type, widely used for hardware, plumbing fixtures, and musical instruments, contains around 70% copper and 30% zinc. The higher copper content contributes to a more yellowish color, good workability, and formability.

C360 Brass (Cartridge Brass): This type, employed in making ammunition shells due to its strength and ductility, has a composition of around 60% copper and 40% zinc. The increased zinc content makes the brass harder and more resistant to wear.

Factors Affecting Composition:

The specific percentage of copper and zinc used in brass is determined by several factors, including:

Desired Properties: Depending on the application, the brass needs to be strong, ductile, have a specific color, or be resistant to corrosion. Adjusting the copper-zinc ratio helps achieve these tailored properties.

Machinability: For applications requiring easy shaping and machining, a higher zinc content might be preferred.

Cost: Copper is generally more expensive than zinc. Manufacturers may optimize the composition to balance cost and desired properties.

Conclusion:

While the exact composition can vary, in most common brass alloys, you'll find around 30% zinc and 70% copper. This ratio provides a good balance between workability, strength, and cost-effectiveness for various applications.