High-strength high-conductivity materials have wide application to magnetic coils, electric power lines, electronics devices etc. as shown in figure 19.1. To get a high value of electrical conductivity, the reduction of interstitial as well as substitutional atoms is essential according to Linde’s rule. Taking account of this, available factors for the strengthening are (a) precipitation, (b) refinement of microstructure and (c) second phase, i.e. a composite.