Means of increasing the wear resistance of hard alloys, high-speed steel, and high-carbon steel used in cutting tools are considered. Chemicothermal hardening is employed: specifically, diffusional saturation with boron and chromium (chromoboriding) for VK8 sintered tungsten–cobalt alloy and with boron and titanium (titanoboriding) for P6M5 high-speed steel. Attention focuses on VK8 alloy and P6M5 steel because of the increasing industrial use of high-strength, low-wear materials. Their chemical composition and microhardness are investigated; the microhardness of the diffusional coatings obtained is measured. The results indicate that chemicothermal treatment of tool materials is a promising means of improving their strength and performance.

The spinning cup, a crucial component of textile equipment, relies heavily on 2A12 aluminum alloy as its primary raw material. Commonly, electroplating and chemical nickel–phosphorus (Ni-P) plating are employed to improve the surface characteristics of the object. Nevertheless, due to the growing expectations for the performance of aluminum alloys, the hardness and wear resistance of Ni-P coatings are no longer sufficient to fulfill industry standards. This study primarily focuses on the synthesis of Ni-B-PTFE nanocomposite chemical plating and its effectiveness when applied to the surface of 2A12 aluminum alloy. We examine the impact of the composition of the plating solution, process parameters, and various other factors on the pace at which the coating is deposited, the hardness of the surface, and other indicators of the coating. The research findings indicate that the composite co-deposited coating achieves its optimal surface morphology when the following conditions are met: a nickel chloride concentration of 30 g/L, an ethylenediamine concentration of 70 mL, a sodium borohydride concentration of 0.6 g/L, a sodium hydroxide concentration of 90 g/L, a lead nitrate concentration of 30 mL, a pH value of 12, a temperature of 90 °C, and a PTFE concentration of 10 mL/L. The coating exhibits consistency, density, a smooth surface, and an absence of noticeable pores or fissures. The composite co-deposited coating exhibits a surface hardness of 1109 HV_0.1, which significantly surpasses the substrate’s hardness of 232.38 HV_0.1. The Ni-B-PTFE composite coating exhibits an average friction coefficient of around 0.12. It has a scratch width of 855.18 μm and a wear mass of 0.05 mg. This coating demonstrates superior wear resistance when compared to Ni-B coatings. The Ni-B-PTFE composite coating specimen exhibits a self-corrosion potential of −6.195 V and a corrosion current density of 7.81 × 10⁻⁷ A/cm², which is the lowest recorded. This enhances its corrosion resistance compared to Ni-B coatings.

Широкое использование в современном машиностроении конструкционных алюминиевых сплавов АМг6 и В95 привело к выявлению такой проблемы, как неоптимальная структура коммерческих полуфабрикатов из этих сплавов. Традиционные виды термической обработки не всегда позволяют достичь исправления структуры и получения высокого комплекса эксплуатационных свойств. Наиболее часто встречающимися дефектами структуры коммерческих полуфабрикатов из алюминиевых сплавов, содержащих магний и цинк, является полосчатость, образованная упрочняющей интерметаллидной фазой MgZn2. Методами оптической микроскопии высокого разрешения исследована структура магниевых алюминиевых сплавов при различных режимах термической обработки, заключающейся в длительном гомогенизационном отжиге. Исследования проводили на образцах из сплавов АМг6 и В95. Для термообработки использовали камерную печь типа СНОЛ, оборудованную ПИД-регулятором, образцы загружали в предварительно разогретую до температуры 500 °С печь и выдерживали в ней в течение 8 и 16 ч. По завершении выдержки, образцы извлекали из печи и охлаждали на спокойном воздухе. Измерение твердости производили на исходных образцах, образцах после термообработки и спустя 14 суток после термообработки. Исследования показали, что увеличение времени высокотемпературной выдержки при 500 °С для обоих сплавов приводит к растворению интерметаллидных частиц. В результате происходящих структурно-фазовых превращений при дальнейшем охлаждении и последующем естественном старении, интерметаллидная фаза вновь выделяется из твердого раствора, как показали измерения твердости, произведенные на исходных образцах, затем после высокотемпературного отжига и в последующем – после естественного старения в течение 14 суток.

The widespread use of structural aluminum alloys AMg6 and V95 in modern mechanical engineering has led to the identification of such a problem as the non-optimal structure of commercial semi-finished products from these alloys. Traditional types of heat treatment do not always make it possible to correct the structure and obtain a high complex of operational properties. The most common structural defects in commercial semi-finished aluminum alloys containing magnesium and zinc are banding formed by the strengthening intermetallic phase MgZn₂. The structure of magnesium–aluminum alloys has been studied by high-resolution optical microscopy under various heat treatment modes, which include long-term homogenization annealing. The studies were carried out on samples of AMg6 and V95 alloys. For heat treatment, a chamber furnace of the SNOL type equipped with a PID controller was used; the samples were loaded into a furnace preheated to a temperature of 500°C and kept in it for 8 and 16 h. After the exposure was completed, the samples were removed from the furnace and cooled in still air. The hardness was measured on the original samples, samples after heat treatment and 14 days after heat treatment. Studies have shown that an increase in the time of high-temperature holding at 500°C for both alloys leads to the dissolution of intermetallic particles. As a result of the ongoing structural-phase transformations during further cooling and subsequent natural aging, the intermetallic phase again precipitates from the solid solution, as shown by hardness measurements made on the original samples, then after high-temperature annealing and subsequently after natural aging for 14 days.

GCr15 bearing steel is widely used in the textile, aerospace, and other industries due to its excellent mechanical properties. However, traditional electroless Ni-B coatings can no longer meet the growing demand for a long service life under high-speed and heavy load conditions. This study focused on depositing Ni-B-Mo alloy coatings on GCr15 steel. An orthogonal experimental design was adopted to investigate the effects of the NiCl₂ and Na₂MoO₄ concentrations and deposition time on the deposition rate and surface hardness of the coatings. The results show that the Na₂MoO₄ concentration has the most significant impact on the deposition rate. An optimal concentration of 5.6 g/L improved both the deposition rate and hardness (up to 881 HV), while excessive Na₂MoO₄ (>15.6 g/L) reduced the coating adhesion and wear resistance. A deposition time of 1–2 h ensured a high deposition rate, but after 3 h, bath component depletion lowered the rate and caused coating defects. The NiCl₂ concentration (20–30 g/L) had a relatively minor influence on the deposition rate but stabilized the Ni²⁺ ion supply, enhancing the coating compactness. The optimized parameters were 5.6 g/L Na₂MoO₄, 25 g/L NiCl₂, and 2 h of deposition. The coating exhibited high hardness, strong adhesion, and excellent wear resistance. After heat treatment at 400 °C for 1 h, the coating transitioned from being amorphous to nanocrystalline, forming Ni₂B, Ni₃B, and Mo₂C phases, increasing the hardness from 737.49 HV to 916.19 HV and reducing the friction coefficient to 0.38.