Mechanisms of erosion and degradation in Ti2SnC during arc discharge across varying gas mixtures

This study investigated the erosion and degradation mechanisms of Ti 2 SnC during arc discharge at 9 kV across varying gas mixtures (N 2 /CO 2 , SF 6 /CO 2 , SF 6 /N 2 ) using a custom-built experimental setup with controllable ambient atmosphere. Arc parameters were recorded in real time using an oscilloscope. The microscopic and three-dimensional morphologies of the eroded zones were examined by scanning electron microscopy (SEM) and three-dimensional laser scanning confocal microscopy (3D SLCM). The composition of the eroded regions was characterized through X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), revealing the arc erosion mechanism of Ti 2 SnC in these mixed atmospheres. The results demonstrate that arc parameters are significantly influenced by the ambient atmosphere. The highest arc energy, arc duration, and eroded area were observed in the N 2 /CO 2 mixture, decreasing in the order N 2 /CO 2 , SF 6 /CO 2 , SF 6 /N 2 , while the breakdown strength exhibited the opposite trend. The eroded regions in all mixed atmospheres exhibited an approximately elliptical shape with typical arc erosion features such as protrusions, craters, pores, and cracks, the morphology of which is governed by the arc structure. The ionization priority of the mixed atmosphere and the arc energy collectively determine the composition of the final erosion products: SnO 2 and TiO 2 predominantly formed in N 2 /CO 2 , SnO 2 and SnF 4 were the main products in SF 6 /CO 2 , and Sn 3 N 4 was primarily generated in SF 6 /N 2 . This research expands the application scope of MAX phase materials and provides a theoretical foundation for the design of novel electrical contact materials.