List the most important properties of copper, and explain why copper is a suitable material for automobile radiators, cooking utensils, and electrical wires. For each application, list other competing materials, and specify the advantages of disadvantages of using copper over these other materials.

Question

What will be an ideal response?

Answer 1

Solution:
Important properties of copper are: high electrical conductivity, high thermal conductivity, good strength, good corrosion resistance, ease of casting, forming, and machining. For automobile radiators and cooking utensils, good thermal conductivity is required, making copper a suitable material. For electrical wires, good electrical conductivity is required.
Aluminum is a good competing material. Its advantage over copper is the lighter weight and cost. Also for cooking utensils, copper needs coating, usually by tin, to protect it from the food or vice versa. Aluminum does not need a coating.
For electrical wires, (particularly transmission cables), the lower strength of Al leads to its sagging. Usually a steel wire is incorporated in the cable to carry the load. Even then, aluminum cables cost less. However, the contact resistance of aluminum may become a serious factor so that the joining of cables requires brazing, rather than a simpler process of soldering. At one time, aluminum wires were used for internal wiring of buildings. This has been largely discontinued because of problems associated with connecting aluminum wires to electrical outlets where arcing at contacts have proven to be difficult to eliminate.