scholarly journals Investigation of the electrospark coating, alloying and strengthening technology

2021 ◽  
Vol 21 (3) ◽  
pp. 253-259
Author(s):  
S. P. Glushko

Introduction. The work objectives were the analysis and application of the technology of electrospark deposition of wear-resistant metal coatings on cutting tools or machine parts for their hardening or dimensional restoration.Materials and Methods. The technology, device and principle of operation of the modernized installation intended for electric spark application of wear-resistant metal coatings with composites T15K6, VK8 and VK6 are considered.Results. To determine the parameters of the upgraded electrospark alloying plant, experiments were carried out on hardening of polished samples made of steel 45 with hard alloy T15K6 with dimensions of 25×25×25 mm. As a result of using the experiment planning method, the possibility of selecting and adjusting the installation parameters was confirmed. The following parameters were selected for hardening samples made of steel 45 with hard alloy T15K6: current I = 1-2–A, voltage U = 40-75 V, capacitor bank capacity = 60–100 µF.Discussion and Conclusions. The use of carbon dioxide as a protective medium enables to increase the number of passes and, accordingly, the number of coating layers to twenty, to obtain a total thickness of up to 0.3 mm with a dense structure without oxides. Coatings of this thickness make it possible not only to strengthen, but also to restore the dimensions of worn machine parts. The parameters of the technological modes of electrospark alloying significantly affect the intensity of coating application and the quality of the resulting surface. A rise in the electrical parameters causes an increase in the intensity of each individual discharge and, within certain limits, contributes to an increase in the amount of the transferred coating material, as well as to deeper transformations of the coated surface in the discharge zone. Thus, an electrospark alloying plant equipped with monitoring and diagnostic tools, as well as with a protective gas supply system, can be used for hardening and restoring machine parts and cutting tools.

2021 ◽  
Vol 341 ◽  
pp. 00032
Author(s):  
Aleksandr Kolomeichenko ◽  
Nikolay Titov ◽  
Aleksеy Kolomeichenko

The paper presents the results of theoretical studies that allow predicting the formation of wear-resistant coatings on the working surfaces of machine parts by the method of carbo-vibro-arc hardening (CVAH). Analytical regularities of electric field intensity formation by oscillating carbon electrode during carbo-vibro-arc hardening (CVAH) have been established; the maximum layer thickness of multicomponent paste, 2.1...2.5 mm, which ensures stable electric arc combustion during CVAH, has been theoretically substantiated. With the increase of amplitude and frequency of oscillations of the carbon electrode, the electric field strength at CVAH decreases nonlinearly, but the thickness of the hardened layer of the multicomponent paste has the greatest influence on it. As a result, ceramic-metal coatings of high quality and integrity are formed on the hardened surfaces of parts. The testing of the obtained theoretical regularities has confirmed their reliability.


Author(s):  
Andrej K. Kuleshov ◽  
Vladimir V. Uglov ◽  
V. M. Anishchik ◽  
V. A. Firago ◽  
D. P. Rusalski ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1153
Author(s):  
Ivan Pavlenko ◽  
Jozef Zajac ◽  
Nadiia Kharchenko ◽  
Ján Duplák ◽  
Vitalii Ivanov ◽  
...  

This article deals with improving the wear resistance of multilayer coatings as a fundamental problem in metal surface treatment, strengthening elements of cutting tools, and ensuring the reliability of machine parts. It aims to evaluate the wear depth for multilayer coatings by the mass loss distribution in layers. The article’s primary purpose is to develop a mathematical method for assessing the value of wear for multilayer steel-based coatings. The study material is a multilayer coating applied to steel DIN C80W1. The research was performed using up-to-date laboratory equipment. Nitrogenchroming has been realized under overpressure in two successive stages: nitriding for 36 h at temperature 540 °C and chromizing during 4 h at temperature 1050 °C. The complex analysis included several options: X-ray phase analysis, local micro-X-ray spectral analysis, durometric analysis, and determination of wear resistance. These analyses showed that after nitrogenchroming, the three-layer protective coating from Cr23C6, Cr7C3, and Cr2N was formed on the steel surface. Spectral analysis indicated that the maximum amount of chromium 92.2% is in the first layer from Cr23C6. The maximum amount of carbon 8.9% characterizes the layer from Cr7C3. Nitrogen is concentrated mainly in the Cr2N layer, and its maximum amount is 9.4%. Additionally, it was determined that the minimum wear is typical for steel DIN C80W1 after nitrogenchroming. The weight loss of steel samples by 25 mg was obtained. This value differs by 3.6% from the results evaluated analytically using the developed mathematical model of wear of multilayer coatings after complex metallization of steel DIN C80W1. As a result, the impact of the loading mode on the wear intensity of steel was established. As the loading time increases, the friction coefficient of the coated samples decreases. Among the studied samples, plates from steel DIN C80W1 have the lowest friction coefficient after nitrogenchroming. Additionally, a linear dependence of the mass losses on the wearing time was obtained for carbide and nitride coatings. Finally, an increase in loading time leads to an increase in the wear intensity of steels after nitrogenchroming. The achieved scientific results are applicable in developing methods of chemical-thermal treatment, improving the wear resistance of multilayer coatings, and strengthening highly loaded machine parts and cutting tools.


2020 ◽  
Vol 385 ◽  
pp. 125402 ◽  
Author(s):  
Alexey Vereschaka ◽  
Vladimir Tabakov ◽  
Sergey Grigoriev ◽  
Nikolay Sitnikov ◽  
Filipp Milovich ◽  
...  
Keyword(s):  

2010 ◽  
Vol 30 (9) ◽  
pp. 910-920 ◽  
Author(s):  
F. V. Kiryukhantsev-Korneev ◽  
N. A. Shirmanov ◽  
A. N. Sheveiko ◽  
E. A. Levashov ◽  
M. I. Petrzhik ◽  
...  

2011 ◽  
Vol 52 (1) ◽  
pp. 109-114 ◽  
Author(s):  
I. V. Blinkov ◽  
V. N. Anikin ◽  
R. V. Kratokhvil ◽  
A. N. Ivanov ◽  
M. I. Petrzhik ◽  
...  

2000 ◽  
Vol 125 (1-3) ◽  
pp. 251-256 ◽  
Author(s):  
Y.F. Ivanov ◽  
V.P. Rotshtein ◽  
D.I. Proskurovsky ◽  
P.V. Orlov ◽  
K.N. Polestchenko ◽  
...  

Author(s):  
Anatoly M. Buglaev ◽  

Choosing effective methods and devices for surface hardening of wood-cutting tools is problematic due to the variety of their designs and operating conditions. In this regard, the development of such devices becomes an urgent task. According to the literature, one of the effective methods for increasing the service life of machine parts and tools is electrospark hardening or electrospark alloying. Industrial electrospark installations such as “EFI” (electrophysical measurements) and “Elitron” with manual vibrators are used for electrospark hardening. However, using manual vibrators significantly increases the labour intensity and hardening time. Moreover, the surface quality after hardening with manual vibrators is often unsatisfactory. Various mechanized installations have been developed in order to reduce the labour intensity of electrospark hardening. Nevertheless, these installations are designed to harden specific parts and do not allow hardening tools of various designs, including woodcutting tools. The surface quality after hardening in mechanized installations does not always satisfy the customer. Further surface plastic deformation treatments, such as rolling and unrolling with rollers and balls, as well as diamond burnishing, are often used to improve the surface quality after electrospark hardening. The surface quality after additional processing by these methods boosts, although the labour intensity and cost of the hardening process increase. To increase the wear resistance of machine parts and tools, it is reasonable to reduce the height parameters of roughness, increase microhardness, and form the residual compressive stresses, which is ensured by the methods of surface plastic deformation. In this regard, it becomes necessary to use electrospark hardening simultaneously with surface plastic deformation. The work presents the design and features of using the device for hardening. The device was used to strengthen the thicknesser machine knives, which made it possible to almost double their durability. Applying this device, in comparison with using the electrospark hardening with a manual vibrator, reduces the roughness of the hardened surface and improves the surface quality of the processed workpieces. The modes of hardening have been installed, making it possible to effectively harden wood-cutting tools. For citation: Buglaev A.M. Device for Wood-Cutting Tool Hardening. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 134–141. DOI: 10.37482/0536-1036-2021-5-134-141


2018 ◽  
Vol 224 ◽  
pp. 01051
Author(s):  
Evgeniy V. Artamonov ◽  
Vitaliy V. Kireev ◽  
Vitaliy A. Zyryanov

Nowadays Russian manufacturers of metal-cutting tools for machine-building industry do not offer structures of prefabricated cutting hobs with retrofittable carbide blades for processing of tooth wheels, though usage of retrofittable carbide blades allows to increase significantly working capacity and productivity of the processing. As of today creation of an assembly cutting tool for processing of tooth wheels with the retrofittable carbide blades is a big step forward for machine-building industry. A high quality tool allows warranting for a new equipment and making work of operators more productive. This paper offers a new technical solution providing increase of efficiency of processing by assembly tools with the retrofittable carbide blades made of a hard alloy. Due to usage of progressive cutting patterns division of a margin for straight-line segments and curved sections is performed. This division has a positive impact on cutting hard-alloy inserts and also reduces their wear and tear.


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