(60 - 40 Brass) is known as _______ metal.

Explanation:

Muntz metal:

• Muntz metal, also called Yellow Metal, is an alpha-beta brass alloy consisting of 60 percent copper and 40 percent zinc, and a trace of iron.
• The alloy must be worked hot and is used today for corrosion-resistant machine parts.
• Alpha-beta (also called duplex) metals contain both the α and β phases.
• The α phase refers to a crystal structure that is face-centered cubic, while the β phase is body-centered cubic.
• Its original application was as a replacement for copper sheathing on the bottom of boats, as it maintains the anti-fouling abilities of pure copper.

Gunmetal:

• Gunmetal is an alloy of Copper, Tin, and Zinc.
• An alloy of Copper (88%), Tin (8-10%), and zinc (2-4%).
• Gunmetal is corrosion-resistant to steam and water.
• It is used to make guns, barrels, gears and bearings, steam, and hydraulic casting.