Co-Mo-W Galvanochemical Alloy Application as Cathode Material in the Industrial Wastewater Treatment Processes

The article deals with the role of electrodes materials in improving the industrial wastewater treatment from pollutants by electrochemical action. The instability constants of the complexes and coordinated ligand molecules were calculated. Based on the research conducted regarding the rationalisation of the poly-ligand electrolytes and electrolysis modes, a variative flow scheme of the coatings deposition by triple alloy has been developed. The corrosion resistance characteristics of the coatings obtained in the form of alloy, that were obtained from complex electrolyte that satisfy the necessary coatings requirements for effective treatment of wastewater have been researched. The obtained coatings have better corrosion resistance than in special steels of electrochemical purpose.

Composition and Properties of High-Entropy CrZrTiNiCu Coating

In this work, a high-entropy alloy and CrZrTiNiCu coating were synthesized by mechanical alloying. It is shown that the microhardness of the CrZrTiNiCu coating is not inferior to and in most cases exceeds the hardness of high-entropy equiatomic alloys. The wear resistance of such a coating is 3·10-4 g/min, which also corresponds to special steels in terms of wear resistance. The high-entropy coating has a low coefficient of friction. It turns out to be antifrictional, which obviously leads to energy savings. For the first time, the surface energy, contact potential difference and work function of electrons for CrZrTiNiCu coating were determined.

Trends of manufacture and the Russian market of metallic medical products

The article describes state of the Russian market of medical instruments and equipment, the volume of production, import and export of medical instruments based on metals, and assesses the import dependence on various market segments. The comparative analysis of domestic alloys and materials produced by foreign companies has shown that Russia has developed unique alloys and steels that have no analogues abroad, with improved indicators of corrosion resistance, wear resistance, static and cyclic strength. However, metallurgical products supplied to the medical industry do not always meet the quality requirements, and medical industry enterprises use imported types of metallic products. It should be noted that for medical purposes, lowtonnage production batches are required, which are associated with increased costs. The situation is aggravated by the fact that some of the enterprises that produced low-tonnage batches of special steels and alloys were completely liquidated. In this regard, it is necessary to create a specialized manufacture of such materials. Results of the analysis of the Russian market of special metals and alloys used for medical needs are presented, and ways to solve the problem of import substitution in this market are suggested.

Electrocoagulation Based Chromium Removal Efficiency Classification Using Logistic Regression

Surface treatment and tanning industries use huge quantities of heavy metals—especially Chromium (III) and (VI)—in their processes thanks to its physical proprieties. It is used in the composition of special steels and refractory alloys. By dint of using this metal, an enormous quantity of rejects is produced each year and discharged into the oceans. As this is very dangerous for our environment, it is very important to treat these discharges before getting rid of them. This study treats chromium removal as a special type of heavy metals that can be a component of industrial discharges. Electrocoagulation is considered among the best methods used in this kind of treatment. However, it requires a lot of time, energy and remains expensive. This paper presents a predictive model in order to classify the chromium removal efficiency using electrocoagulation method. The proposed model is a logistic regression (LR) that consumes four parameters that we call predictors: pH, time, current, and stirring speed. After the training and validation process, we obtained 88% as classification precision, recall and F-Score metrics values while the use of the 10-Folds cross-validation method gave a minimal area under curve (AUC) value of 97% while the best value attempts 100%. Classification report states that the model performs well comparing to similar experimentation efficiencies.

Evaluation of carbide capacity in CaO-based ternary systems at 1773k for refining process

Refining slags is widely used in the production of high-value-added alloys and special steels. The removal of impurities depends on the mass transfer between the slag-metal interface, and the carbide capacity of the refining slags is crucial to control the carbon content in the final products. A phenomenological model is introduced in this article for the calculation of carbide capacity of different CaO-based ternary refining slags. The contour lines of carbide capacity in CaO-Al2O3- CaF2, CaO-SiO2-CaF2 CaO-SiO2-MnO systems are calculated based on limited experimental data by the present model. The experimental data within the calculation boundary are compared with the predicted values and satisfactory agreements are observed with the mean deviation being 1.4%, 2.3%, and 1.6%, for these three systems respectively. The present model is powerful and flexible in the calculation of carbide capacity of CaO-based ternary refining slags and can be applied to other systems.

Design of The Vibrostabilisation Stand For Reducing Residual Stresses in Discs Used In The Construction of Multi-Plate Clutches and Brakes

Heavy-duty, oil-cooled brake discs (MMOTs) are often used in heavy-duty brake systems manufactured by companies such as Caterpilar, Clark, Komatsu and Liebherr. These discs are usually made of special steels, and in most cases, the flatness of the working surfaces should not exceed 0.15–0.30 mm. Although the technological processes of friction disc production include several stages of heat treatment and grinding, the required accuracy is not achieved in some cases. In addition, the remaining residual stresses lead to the deformation of the discs during their lifetime. In production practice, three methods are used to reduce residual stresses: thermo-fixing, dynamic stabilisation and vibratory stabilisation consisting in bringing discs to transverse resonance vibrations and maintaining resonance until significant stress reduction. The article proposes a method of stabilising the discs using the resonance phenomenon at the first few frequencies. In this article, Cauchy’s function method and characteristic series method are used to develop solution value problem for clamped circular plates with discrete inclusions as concentrated masses and springs. Calculation methods for quick estimation of the own frequency of discs with additional ring mass enabling the use of low power vibration inductors are presented. The use of a special membrane and a pneumatic cushion in the construction of the stand allows to induce vibrations of higher frequencies.