Features of the microstructure of the silicon carbide coating on a tungsten filament

   
A.Shlapak
 

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Omeliana Pritsaka str.,3, Kyiv, 03142, Ukraine
Electron Microscopy and Strength of Materials - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2018, #24
http://www.materials.kiev.ua/article/2672

Abstract

The study of metallography and electron microscopy of samples of composite fibers (tungsten wire with a coaxial silicon carbide coating) showed that the microstructure of the SiC samples contains the following components in the form of layers: the layer adjacent to the W-wire surface is the diffusion zone W in SiC, the following two components are the layers of the SiC coating, which consist of radially positioned elongated twinned grains. The surface of the outer layer (microrelief) is composed of the growth of SiC microcrystals. As the size of the elements of the microstructure of the coating increases, the tensile strength of the fibers decreases. It was also found that in fibers with reduced strength there was an enlargement of the formations of the composition of W—Si—C in the diffusion zone W—SiC. Full text download


COATINGS, CRYSTALS, GRAIN, LAYER, MICROSTRUCTURE, SILICON CARBIDE, TUNGSTEN WIRE