Copper Conductivity: Effects of Alloying Elements

This lecture discusses the conductivity of copper and how it is influenced by various alloying elements. It begins with an overview of copper's excellent electrical and thermal conductivity, highlighting its sensitivity to alloying elements. The instructor explains the phase diagrams of copper-oxygen systems, detailing how oxygen can dissolve in copper and form oxides like Cu2O and CuO. The lecture further explores the phenomenon known as 'hydrogen disease' in copper, where hydrogen diffuses into the metal, leading to the formation of water vapor and weakening the material. Solutions to mitigate this issue include using oxygen-free high conductivity copper or alloying with elements like phosphorus. The discussion also covers the mechanical properties of copper alloys, including those with silver, cadmium, and chromium, which enhance strength while maintaining conductivity. The lecture concludes with a look at the role of lead in copper alloys, emphasizing its impact on machinability and the challenges of replacing lead in industrial applications.