Comparison of Electrical Properties of CuCr30 Contacts Manufactured by Two Powder Metallurgy Technologies

The powder metallurgy CuCr contacts has excellent anti-welding performance, thus it is often used in low contact pressure Vacuum Interrupters (VIs), which are typically used in VIs commercially made by Russia. Compared with the CuCr contact which is made by the arc melting or vacuum melting, the disadvantage of powder metallurgy CuCr contact is that its current breaking capacity is low. This research focused on an improvement of breaking capacity of CuCr30 contacts by using Spark Plasma Sintering (SPS) sintering process. The current breaking capacity and welding strength was compared with conventional powder metallurgy CuCr30 contacts. The experimental results showed that the SPS sintering process improved the electrical life. The conventional powder metallurgy processed CuCr30 contacts successfully interrupted short circuit current of …kA with 13 times, while the SPS process sintered CuCr30 contacts reached 19 times, even though it is still lower than that of the vacuum melting CuCr30 contacts (22 times) and the arc melting process contacts (23 times). The average welding force of the conventional powder metallurgy and SPS processes CuCr30 contact were 441.8N and 348.9N, respectively.