Study of the temperature dependence of a carbidized layer formation on the tungsten surface under plasma irradiation

Abstract

The paper considers a method of tungsten surface carbidization using a beam-plasma discharge (BPD), which was implemented in a plasma-beam installation (PBI). The advantage of this method is to create conditions for chemical reactions and physical processes as close as possible to those possible in thermonuclear installations. The BPD makes it possible to generate plasma using different working gases. Methane was used as a plasma-forming gas. The working gas pressure in a chamber was (1,3-1,4)·10-1 Pa. The temperature dependence of the carbidized layer formation on the tungsten surface under plasma irradiation was determined in the temperature range of 700-1700 °C. The formation of tungsten carbides in surface layers was confirmed by SEM and X-ray diffraction analysis. It was found that interaction between tungsten and methane in a wide temperature range can proceed with simultaneous or sequential formation of the carbide phases W2C and WC.

Research of the Structural-Phase State of Tungsten Surface Layer Cross-Section After Carbidization in a Beam-Plasma Discharge Usage Electron Microscopy Methods

“…The method of tungsten surface carbidization using a beam-plasma discharge is described in [8,9] and implemented on a plasma-beam installation (PBI). A detailed description of the installation is presented in [10][11][12].…”

“…A detailed description of the installation is presented in [10][11][12]. In paper [9], the temperature dependence of the carbidized layer formation on tungsten surface under plasma irradiation in the temperature range of 700-1700 °C was studied. The tungsten carbide formation in the surface layers was confirmed by X-ray analysis and SEM.…”

“…The papers [8,9] present the results of studying the formation of a carbidized layer on the tungsten surface using a beam-plasma discharge (BPD). Methane was used as a working gas during the ignition of the PBD.…”

Influence of the Carbidized Tungsten Surface on the Processes of Interaction with Helium Plasma

“…The total number of tungsten samples in accordance with the results presented in this paper was 6 pcs, including 2 samples with a WC carbide layer and 2 samples with a W 2 C carbide layer. According to the results of our recent work [ 35 ], the thickness of the carbide layer was in the range from 1.6 to 4.2 µm. The tungsten samples were discs cut from a bar of the highest purity (HP) with a height of 2.0 ± 0.1 mm and a diameter of 10 mm (S = 0.78 cm 2 ) via the electroerosion method.…”

“…In accordance with the method previously developed by us [ 36 ], the carbide surface layers were obtained in the form of WC tungsten carbide and W 2 C tungsten semi-carbide. The results of the tungsten carbidization process studies are described in [ 35 , 37 ].…”