Investigation on the arc erosion performance of Ag–Ta2AlC composite under air conditions

Abstract

The Ta2AlC material is designed to enhance the performance of Ag-based electrical contact materials as a reinforcement phase. With a work function of 6.7192 eV, Ta2AlC demonstrated significantly higher values than reinforcement phase materials such as SnO2, ZrO2, and the commonly used MAX phase materials. Consequently, the arc erosion performance of an Ag–Ta2AlC composite was investigated under air conditions. Gas breakdown mainly occurred due to electron avalanches, with the observation of a streamer breakdown mechanism in a strongly nonuniform field. The arc exhibited concentrated erosion on the surface of the Ag–20 vol% Ta2AlC material, resulting in a higher arc energy. As the volume fraction of the Ta2AlC material increased to 30% and 40%, the eroded area became more dispersed. In particular, Ag–30 vol% Ta2AlC displayed the lowest arc energy (3.395 kJ) and shortest arcing time (33.26 ms). Among the four tested components, the Ag–30 vol% Ta2AlC composite demonstrated superior arc erosion resistance. Oxides of Ag2O, AgO, Ta2O5, and Al2O3 were formed through the interaction of ionized Ag and Ta2AlC particles. By combining the electromagnetic force and plasma flow force, sputtered particles and bulges were generated on the eroded surface. These research findings contribute to broadening the applications of Ag–MAX materials in the realm of electrical contacts.

Keywords

• max phase
• electrical contact materials
• surface oxidation
• arc erosion
• streamer