Fabrication and arc erosion behaviors of AgTiB2 contact materials

To clarify the relation of TiB2 particle size and the arc erosion behaviors, two kinds of Ag-4wt.% TiB2 contact materials were consolidated by powder metallurgy using ultrafine and coarse TiB2 powders. The arc erosion test was made 30 times, the erosion morphologies of Ag-4wt.% TiB2 contact materials after arc erosion were characterized, the spatial distribution of TiB2 particles in Ag matrix was evaluated, and the arc duration and mass losses before and after arc erosion were determined as well. From SEM images, it can be seen that large and deep erosion pits are present on the contact surface of the Ag-4wt.% TiB2 contact material consolidated using coarse TiB2 powders, while the erosion pits become shallower and are distributed more dispersedly for the Ag-4wt.% TiB2 contact material consolidated by ultrafine TiB2 powders. It suggests that ultrafine TiB2 particles can improve arc erosion resistance.