Comparative Study of the Properties of Cu-Cr-Mo System Electrical Contact Material by Sintering and Infiltration Methods

Abstract

Contact materials in high-voltage vacuum interrupters require properties such as high conductivity, density and hardness to minimize arc heat damage. In this study, Cu–Cr–Mo alloy contact materials were examined for their usage as high-voltage contact materials. Ball milling was performed after analyzing the raw materials of the Cu, Cr and Mo powders. A green compact was produced using high pressure with a mixed powder. Subsequently, the composite was produced by sintering via the temperature and infiltration method according to the Cu content in the green compact. The composite sintering method produced a density of 8.55 g/cm3 (relative density 93%), a hardness of 217 HV and an electrical conductivity of 40.7% IACS at 1200 °C. The composite of 10 wt.% Cu produced by the Cu infiltration method exhibited a density of 8.7 g/cm3 (relative density 94%), hardness of 274 HV and electrical conductivity of 39 IACS% at 1300 °C. The measurements of the physical properties of our newly established method demonstrated a new possibility of using the Cu–Cr–Mo alloy as a contact material for high-voltage vacuum interrupters.

Keywords

• electrical contact material
• Cu–Cr–Mo
• liquid phase sintering
• infiltration method