RESEARCH OF THE STRUCTURAL-PHASE STATE OF TUNGSTEN SURFACE LAYER CROSS-SECTION AFTER CARBIDIZATION IN A BEAM-PLASMA DISCHARGE USAGE ELECTRON MICROSCOPY METHODS

Abstract

This paper presents research results on the structural-phase state of a tungsten surface layer cross-section after carbidization in a beam-plasma discharge. Tungsten surface carbidization in a beam-plasma discharge was conducted in a plasma-beam installation (PBI). Research on the cross-section structure of the surface layer of tungsten samples after carbidization at temperatures of 1000 °C, 1200 °C, and 1400 °C was conducted using transmission and scanning electron microscopy. Based on the results of SEM studies, a multilayer EMF map and local elemental analysis were obtained, based on which the depth of penetration of carbon atoms into tungsten was evaluated. It is established that the penetration depth is ~20 µm. The surface layer fine structure was researched using TEM. For TEM analysis of the tungsten sample cross-section with a carbidized layer, sections were prepared by ion thinning using an Ion Slicer EM-09100 IS unit. According to the research results, it was revealed that after carbidization, tungsten is available in the surface layer mainly in the composition of carbides WC and W2C. On bright-field TEM images of the cross-section of the surface layer of tungsten samples after carbidization at a temperature of 1200 °C and 1400 °C, bending extinction contours are revealed, which indicate the elastically stressed state of the sample surface layer, which leads to bending-torsion of the foil.