Plasma treatment of heat-resistant materials

Refractory lining of thermal generating units is exposed to chemical, thermal, andmechanical attacks. The degree of fracture of heat-resistant materials depends on the chemicalmedium composition, the process temperature and the material porosity. As is known, a shorttermexposure of the surface to low-temperature plasma (LTP) makes possible to createspecific coatings that can improve the properties of workpieces. The aim of this work is toproduce the protective coating on heat-resistant chamotte products using the LTP technique.Experiments have shown that plasma treatment of chamotte products modifies the surface, anda glass-ceramic coating enriched in mullite is formed providing the improvement of heatresistance. For increasing heat resistance of chamotte refractories, pastes comprising mixturesof Bacor, alumina oxide, and chamot were applied to their surfaces in different ratios. It isproved that the appropriate coating cannot be created if only one of heat-resistant componentsis used. The required coatings that can be used and recommended for practical applications areobtained only with the introduction of powder chamot. The paste composition of 50% chamot,25% Bacor, and 25% alumina oxide exposed to plasma treatment, has demonstrated the mostuniform surface fusion

Silica nanoparticles produced by DC arc plasma from a solid raw materials

Plasma synthesis of SiO[2] nanoparticles in experimental atmospheric pressure plasma reactor on the basis of DC arc plasma generator was presented in this paper. Solid high-silica raw materials such as diatomite from Kamyshlovskoye deposit in Russia, quartzite from Chupinskoye deposit in Russia and milled window glass were used. The obtained nanoparticles were characterized based on their morphology, chemical composition and size distribution. Scanning electron microscopy, laser diffractometry, nitrogen absorption (Brunauer–Emmett–Teller method), X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy were used to characterize the synthesized products. The obtained silica nanoparticles are agglomerated, have spherical shape and primary diameters between 10-300 nm. All samples of synthesized nanopowders were compared with commercial nanopowders

Influence of plasma modification of basalt fibers on the physical and mechanical characteristics of peek-based laminates

The results of a study of the effect of pre-treatment of basalt fibers with low-temperature atmospheric discharge plasma with runaway electrons on the physical and mechanical characteristics of polyetheretherketone (PEEK)-based laminates are presented. A comparison is made with the results of studies of similar composites reinforced with carbon fiber subjected to plasma treatment at the same exposure times. It is shown that the use of preliminary plasma modification leads to a significantly better wetting of the fiber surface with a polymer after 5 minutes of treatment. After a 10-minute treatment the signs of degradation of the basalt fiber surface structure are observed, accompanied by the formation of microdamages, which contributes to an increase in adhesion to the binder, but leads to a decrease in the strength characteristics of fibers and composites. When carbon fibers are processed for 10 minutes, small erosion marks appear on their surface, which contribute to an increase in interfacial adhesion, but are not so critical from the standpoint of reducing tensile strength. The revealed discrepancy in the nature of the effect of plasma treatment on basalt and carbon fiber is interpreted by differences in the conductivity properties of reinforcing materials, which affects the intensity of damage to their structure during processing, and, consequently, mechanical characteristics of the fibers and the fiber-reinforced composites