Understanding the Friction Behavior of Niobium Sheets during Forming Processes

Niobium is a material widely used for particle accelerating facilities, such as cavities. These components are usually obtained through forming processes, and then to understand the friction behavior of niobium sheets during the forming process can be very useful. Therefore, in this work the friction behavior of niobium sheets under conditions similar to the ones faced in forming processes has been studied. Pin-on-disk tests have been carried out in both dry and lubricated conditions, and different values of contact force in the range of 2.5 and 20 N have been adopted to observe and understand the tribological behavior of niobium. The worn surfaces have been observed through a scanning electron microscope and EDX analyses to reveal the wear mechanisms. The experimental outcomes proved that niobium exhibits very high friction coefficient with a severe adhesive wear under dry condition, while a lower friction coefficient with a less severe wear mechanism has been observed when lubricant is adopted.