Electrospark Coatings Research Articles

Modeling of wear-resistance of electro-spark coatings without lubricant

In the article experimental data on wear-resistance of electro-spark coatings an aluminum alloy Ал-25 by copper electrode is given. Planning of experiment and mathematical modeling wear-resistance and friction factor is made. An analysis of models is performed.

Corrosion Resistance of Titanium Palladized by Electro-Sparking with Subsequent Anodic Plasma-Heating in Aqueous Electrolyte

The effect of anodic heating in electrolytic plasma (AHEP) on the corrosion and electrochemical behavior of titanium with electro-spark palladium coatings in 10–40% H2SO4 solutions at 100°C is studied. It is shown that the treatment by the AHEP method enhances the corrosion resistance of palladized titanium by more than one exponent. This is due to the formation of palladium-containing oxide–carbide layers.

Improving oxidation resistance of Ti 3Al and TiAl intermetallic compounds with electro-spark deposit coatings

Aluminide coatings were directly applied onto Ti 3Al and TiAl intermetallic compounds using a simple but effective method—electro-spark deposition (ESD). The coating has a typical thickness of 15–20 μm, with gradient composition and metallurgical bonding to the substrate. Isothermal oxidation tests in air at 800 and 900 °C for the time period up to 300 h showed that all coated specimens had much lower oxidation rates than uncoated samples. Furthermore, all coated samples exhibited excellent oxide scale spallation resistance. SEM and XRD analysis indicated that on the coated specimens the oxide scales consisted mainly of dense alumina or alumina with rutile, while on the uncoated samples rutile is the main oxidation product. It was clear that the changes in the oxide nature and microstructure played a critical role in decreasing the oxidation rate and improving the scale spallation resistance.

Phase Composition of Electrospark Tungsten Carbide-Based Coatings after Heating and Isothermal Soaking

A study of phase formation on electrospark coatings with WC ― Co ― Cu electrodes on R6M5 high-speed steel during isothermal heat treatment at the operating temperature of the coating. Copper tungstate CuWO 4has been found to form, with its crystal lattice coherently bound to the basic carbide phase of the coating, tungsten monocarbide, through tungsten semicarbide as intermediary. The results complement the data on phase formation during the application of WC-based coatings and during their subsequent use with sliding friction.

Structure and Properties of Composite Electrospark, Laser, and Magnetron Deposited AlN ― TiB2 Coatings

A comparative investigation of the coatings produced by electrospark alloying, laser gas-powder deposition, and magnetron sputtering using composite AlN ― TiB2 material was carried out. It is shown that the presence of oxygen in the working atmosphere is responsible for the oxidation of aluminum nitride, and also the appearance of refractory compounds of the Ti ― Al ― O system in the coatings. During electrospark and laser alloying globular regions form on the surface by a mechanism of liquid-phase sintering, due to the mass transport of a metallic component from the substrate. The composite layer of a magnetron coating sinters by a mechanism of solid-phase interaction. The dispersion-strengthened structure of electrospark coatings is highly wear resistant, while the continuity, high dispersion, and heterogeneity of the structure of magnetron coatings permits their recommendation for corrosion protection.

Stress state in the surface layers of steel R6M5 after electrospark and laser treatment

Laser irradiation of the electrospark alloyed surface of high-speed steel produced remelting of the surface layer and formation of a broad structure transition zone. This optimized the gradient of properties at the surface. Laser treatment of the electrospark coatings produced tensile stresses in the surface layers, whose magnitude and distribution were dependent on the treatment conditions, as well as the physico-chemical interaction of the refractory compound with molten steel in the liquid pool formed by irradiation.

Properties of Electrospark Coatings on Titanium Alloy

Properties of Electrospark Coatings on Titanium Alloy

Electrospark alloying followed by laser treatment of high-speed steel cutting tools

The effect of electrospark and laser alloying with WC-, TiC-, and TiN-based electrodes on the physicomechanical and working properties of the high-speed steels R6M5 and R6M5K5 was investigated. Laser treatment of electrospark coatings based on refractory compounds increased hardness and heat resistance, and improved the contact properties of cutting tools in their interaction with the chip, thus increasing wear resistance. The optimal conditions of electrospark and laser alloying were determined.

Structure of TiN-Ni electrospark coatings after laser irradiation

Structure of TiN-Ni electrospark coatings after laser irradiation

Electrospark coatings of chromium alloys

Electrospark coatings of chromium alloys

Effect of pulsed laser radiation on the structure and properties of electrospark coatings of type VK and TK alloys

Effect of pulsed laser radiation on the structure and properties of electrospark coatings of type VK and TK alloys

Properties of eutectic electrode materials for electrospark alloying

Electrode materials have been based on a eutectic alloy in the Fe-Mn-C-V system. The optimum component ratio has been determined for the charge along with the general trends in the formation of the modified eutectic alloys. X-ray structure and metallographic results have been reported along with wear-test data for the electrospark coatings.

The influence of burnishing on the properties of electrospark coatings

The influence of burnishing on the properties of electrospark coatings

Structure formation of electrospark coatings of silver on copper substrates

Structure formation of electrospark coatings of silver on copper substrates

Kinetics of the process of formation and high-temperature oxidation of electrospark coatings on steel

Electrospark coatings of TiB2-Mo on steel 45 are marked by improved scaling resistance at temperatures above 900°C. Their scaling resistance and also the effectiveness of the process of ESA increase with increasing content of the phase β-MoB in the coating because molybdenum borate forms during its high-temperature oxidation.

Corrosion resistance of VT1-0 titanium with electrospark coatings

Corrosion resistance of VT1-0 titanium with electrospark coatings

Tribotechnical characteristics of titanium diboride electrospark coatings

The tribotechnical characteristics of an alloyed layer obtained by electroerosion hardening of 45 steel with TiB2-Mo sintered materials were studied. It was established that at increased temperature the maximum wear resistance is possessed by a hardened layer in alloying with a material containing the optimum quantity of hard and plastic phases. A higher content of hard phase leads to brittle failure of the hardened layer and an increased content of plastic phase to seizing of the contacting pairs.