Final answer:
Aluminum branch wiring was extensively utilized as a cost-effective alternative to copper between 1963 and 1974, despite aluminum requiring larger diameters and specific handling due to lesser ductility and expansion issues.
Step-by-step explanation:
Aluminum branch wiring was used as a substitute for expensive copper wire primarily from 1963 to 1974. This was partly due to the high cost of copper; aluminum, while cheaper, required a larger diameter to match the resistance per length of copper wires. Aluminum wiring does not have the same ductility and tensile strength as copper, but the level is still acceptable for specific uses. However, there are significant concerns with aluminum wiring, such as its higher rate of thermal expansion, which can cause connections to loosen over time, potentially leading to fire hazards. The oxidation of aluminum can cause issues since it does not conduct electricity, and special techniques are needed for proper connection and use. Electrical outlets and other components must be designed specifically to work with aluminum wires.
During the era aluminum was often used in household wiring, it replaced copper in many overhead power lines too. Aluminum is still used in power lines today, typically surrounding a steel core which adds strength and prevents the material from breaking when stretched over long distances. In some special cases, materials like gold are used for wiring due to their exceptional resistance to surface corrosion.