1. Bimetallic wire aspects

1.1 Soul of the wire

Conductors for electrical cables are generally made of copper or aluminum, due to the good conductivity of these materials. However, in the case of miniature conductors made up of strands with diameters between 15 and 50 µm, copper alloys with better mechanical properties are often required to compensate for the sharp drop in mechanical strength due to the decrease in diameter. Various alloys have been studied and developed for this purpose. These include beryllium, cadmium and tin alloys. Table 3 summarizes the chemical composition, mechanical and electrical properties of these alloys, as well as those of the metals copper and aluminum. It can be seen that, compared with the metal copper, the alloys have...