Question

Gunmetal contains
1. Cu = 60%, Sn = 40%
2. Cu = 80%, Sn = 20%
3. Cu = 70%, Sn = 30%
4. Cu = 90%, Sn = 10%

Answer 1

Correct Answer - Option 4 : Cu = 90%, Sn = 10%

The correct answer is Cu = 90%, Sn = 10%.

• Alloy: It is a solid-solid mixture of two or more metals and a non-metal.
  • Alloy enhances the property of a particular metal.
• Gunmetal: 
  • It is an alloy of copper, tin, and zinc.
  • It contains 88% copper, 10% tin, and 2% zinc, more precisely.
  • It is used in casting boiler fittings, bushes, bearings, and glands, etc.

• Different alloys:

Alloy	Composition
Brass	Copper (60-80%) Zinc (40-20%)
Bronze	Copper (88%) Tin (12%)
Monel	Nickel (60%) Copper (33%) Iron (7%)
Nichrome	Nickel (80-85%) Chromium (15-20%)
Solder	Lead (50%) Tin (50%)
Magnelium	Magnesium (5%) Aluminium (95%)
Rolled Gold	Copper (90%) Nickel (10%)