One of the modern and effective methods of hardening metals is nitriding in a glow discharge in ammonia or in an anhydrous medium (nitrogen + argon) - BATR. This paper presents the results of experimental studies comparing the results of tribological and physicochemical properties of hardened surfaces obtained by nitriding with autonomous and interconnected BATR modes. The complex of traditionally fixed values of operating parameters (temperature, composition of the gas mixture, pressure and saturation time) without taking into account energy characteristics (voltage, current density and specific discharge power) significantly reduces the technological capabilities of BATR to achieve the necessary physicochemical properties of metal surfaces specified by conditions exploitation. Taking into account the energy characteristics of BATR, a significant reduction in the energy consumption of the nitriding process is achieved. The energy levels of the main subprocesses are significantly different: the formation of nitrides occurs at low energies, surface sputtering occurs at high voltage values, and nitrogen diffusion occurs at increased current density values. In cases where the energy of the flow is insufficient, either a glow discharge may not occur at all, or with a lack of voltage, the nitride ball on the surface is not sprayed and it acts as a barrier that prevents the diffusion process into the inner layers of the metal, which leads to low physicochemical and, correspondingly, tribological indicators of nitrided balls. The quantitative ratio between them and the required operational properties of the metal, respectively, can be achieved only through an independent combination of the energy and operating characteristics of BATR
The effect of acidic, alkaline and neutral media on wear kinetics and mechanism for fluoroplastics and polyolefins has been studied. Equations for fluoroplastic and polyolefin wear intensity are obtained based on the thermochemical and mechanical model of their destruction. The values of the activation energies for the surface destruction onset over the entire wear cycle of the polymer surface spherulite are determined.
The technology of formation of wear-resistant composite electrolytic coatings (CEP) based on nickel-based is presented. CEP. These coatings contained a filler consisting of powders of silicon carbide of various fractions and amorphous boron with a particle size of about 1 μm for further heat treatment. The obtained coatings were tested for their cavitation and erosion resistance in electrolyte media
The article analyzes the influence of composite electrolytic coatings (CEC) on the wear resistance of structural steels. The issues of matrix selection and various combinations in composite coatings of different chemical elements and compounds are considered. Coatings based on chromium, nickel, iron, copper, cobalt and others are widely used in industry, but nickel-based composite coatings are the most widely used. Nickel is widely used as a matrix for CEC, because it has an affinity for most particles used as the second phase and easily forms a coating with them. These coatings are used for corrosion protection, increase of physical and mechanical and chemical parameters, increase of hardness and wear resistance, restoration of the sizes, giving to a surface of self-lubricating properties. Nickel-based coatings with SiC filler of various fractions from size 100/80 μm to nanoparticles smaller than 50 nm were investigated on the basis of the established installation for CEC application. Thus, SiC powders with the following sizes were used in the works: less than 50 nm - nanoparticles; M5; 28/20; 50/40; 100/80 μm. In the studies performed, 0.01… 0.02 g/l sodium lauryl sulfate was additionally introduced into the electrolyte, which promotes the incorporation of SiC particles into the coating and improves the conditions for building the Nickel matrix. Amorphous boron powders of about 1 μm size were also added to the silicon carbides as a filler, which is explained by the possibility of boron and nickel interaction during the subsequent heat treatment of the coating and obtaining new structures (solid solutions, eutectic, dispersion-hard alloys). It is of practical interest to study the possibility of improving the physical and mechanical properties of nickel-based CEC by introducing metals capable of heat treatment, interact with the metal matrix to form solid substitution solutions and chemical compounds (solid phases of implementation) and determine tribotechnical characteristics of these coatings.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.