scholarly journals Оptimization of the chrome plating bath operation during the restoration of vehicle parts

2021 ◽  
Vol 18 (4) ◽  
pp. 390-405
Author(s):  
A. N. Kotomchin
Keyword(s):  
Trivalent Chromium ◽  
Stable Operation ◽  
Plating Bath ◽  
Optimal Amount ◽  
Chrome Plating ◽  
High Productivity ◽  
Chromium Plating ◽  
Chrome Coating ◽  
The Stability

Introduction. In the process of chrome plating of car parts, there is a change in the composition of the chrome plating bath, which affects the stability of the ongoing processes – the performance and quality of the chrome coating. Therefore, it is necessary to constantly monitor the chrome plating bath for the presence of foreign elements that can be formed during the operation of the bath during the reaction of the solution with the anode or cathode.Materials and methods. During the research, the necessary equipment was used, which made it possible to determine with sufficient accuracy the content of trivalent chromium and its effect on the electrolysis process – the performance and quality of chrome coatings. A well-known technique was used to determine the quality and performance.Results. When conducting studies of the obtained cold self-regulating chromium plating electrolyte, it was found that trivalent chromium has a significant effect on the stability of the chromium plating bath. The content of which can vary within 2...25 g/l during operation. As a result, it was found that the optimal amount of trivalent chromium is its content in the chromium plating bath from 2 to 15 g/l. With a lower or higher content, the electrolysis performance and the quality of the chrome coating decrease. It was also found that in order to maintain the optimal amount of trivalent chromium and increase the time for stable operation of the chromium bath, it is necessary to observe the ratio of the area of the anode and cathode (the coated surface of the part), the value of which is within 3...4.Discussion and conclusion. As a result of the conducted research, it will make it possible, under certain conditions, to carry out the process of chromium deposition from a cold self-regulating electrolyte, which will allow for stable chromium deposition at high productivity and the necessary quality of the coatings obtained. The main condition is to control and maintain the amount of trivalent chromium in the chromium plating electrolyte in the bath.

Trivalent chromium electrodeposition using a deep eutectic solvent

2018 ◽  
Vol 65 (5) ◽  
pp. 499-505 ◽  
Author(s):  
Vyacheslav Protsenko ◽  
Lina Bobrova ◽  
Felix Danilov
Keyword(s):  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Diffraction Method ◽  
Trivalent Chromium ◽  
Electrolytic Deposition ◽  
Active Dissolution ◽  
Plating Bath ◽  
Content Type ◽  
Chromium Plating ◽  
New Generation

Purpose This paper aims to investigate the electrolytic deposition of corrosion-resistant chromium coatings from a trivalent chromium plating bath based on deep eutectic solvent, a new generation of room temperature ionic liquids. Design/methodology/approach The electrolyte contained chromium (III) chloride, choline chloride and the additive of extra water. The surface morphology was estimated by means of SEM technique. The microstructure of as-deposited and annealed coatings was studied using X-ray diffraction method. The kinetics of the chromium electrodeposition and the corrosion electrochemical behavior of the coatings were investigated by cyclic voltammetry technique. Findings Chromium coatings with an amorphous type of microstructure are electroplated from this bath. Some carbon and oxygen are included in deposits obtained. The step-wise mechanism of the electrochemical reduction of Cr(III) ions to Cr(0) is detected. The current efficiency in this system sufficiently exceeds that typical of usual aqueous electrolytes. The coatings fabricated using plating bath based on deep eutectic solvent showed enhanced corrosion resistance in an acidic medium: there is no current peak of active dissolution in polarization curve and the corrosion potential shifts to more positive values as compared with “usual” chromium. Originality/value The electrodeposition of chromium coatings from an environmentally acceptable trivalent chromium electrolyte, a deep eutectic solvent containing chloride choline and extra water additive has been investigated for the first time.

Study on the Electrodeposition of Trivalent Chromium Plating Bath in the Presence of Oxalate Anions

2020 ◽  
Vol MA2020-01 (20) ◽  
pp. 1247-1247
Author(s):  
German Orozco ◽  
Julieta Torres-González ◽  
Dennys Fernandez
Keyword(s):  
Trivalent Chromium ◽  
Plating Bath ◽  
Chromium Plating

Main Directions of the Electrochemical Chrome Plating Process Intensification

2020 ◽  
Vol 299 ◽  
pp. 798-804
Author(s):  
Oksana N. Gruba ◽  
Dmitrii V. Ardashev ◽  
Victor P. Chernobrovin
Keyword(s):  
Current Efficiency ◽  
Base Alloy ◽  
Experimental Studies ◽  
Process Intensification ◽  
High Energy ◽  
Process Conditions ◽  
Chrome Plating ◽  
Wear Resistant Coatings ◽  
Chromium Plating

One of the main problems common to all areas of technology is to increase the reliability and durability of machines, devices, and mechanisms. This problem can be solved by applying wear-resistant coatings and chromium-based alloys. The method of electrochemical chrome plating has a number of significant drawbacks: low current efficiency of chromium; the lowest dispersing capacity among galvanic processes; high energy intensity; the presence of high internal stress chrome plating; hydrogenation of chromium sediments and base alloy. Therefore, at present, a large number of works are being carried out aimed at intensifying the processes of chromium plating. This work is aimed at exploring the possibilities of optimizing the process of chrome plating by changing the composition of the electrolyte. Classification of currently used electrolytes of chromium plating was carried out according to the following parameters: electrolyte composition, process conditions, cathode output by current and quality of the coatings obtained. On the basis of experimental studies conducted by the authors, the possibility of intensifying the process of electrolytic chromium plating from aqueous solutions, due to a change in the composition of the electrolyte, is shown. The effect of a number of anions (SO2-4, SiF2-6,Cl-,F-, NH2SO-3, PO3-4, IO3-3, I2O4-7) on the quality of sediments and current efficiency is studied. The ways to improve the most popular universal electrolytes are proposed.

DEVELOPMENT OF A UNIVERSAL AUTOMATIC CONTROL SYSTEM FOR TECHNOLOGICAL PROCESS OF HOLE PROCESSING WITH A MULTI-TOOL

2020 ◽  
Keyword(s):  
Automatic Control ◽  
Transfer Functions ◽  
Stable Operation ◽  
Hydraulic Power ◽  
High Productivity ◽  
Technological Processes ◽  
Automatic Control Systems ◽  
Heavy Loads ◽  
Automatic Systems

The industry serially produces hydraulic power heads, tables designed for drilling, countersinking and boring holes. The disadvantage of these power heads is that they are not universal in terms of the impossibility of rapid changeover from the drilling operation to the reamer. At the same time, two methods of processing holes with multi-blade tools are implemented. The first one is drilling holes in solid metal with a drill, in which the cutting tool experiences heavy loads, leading to premature wear and breakage. The second one is boring of the obtained holes after technological operations of drilling and countersinking, which leads to increased energy costs and labor of operators. The existing fleet of drilling machines, as a rule, is not equipped with automatic control systems of technological processes, allowing to ensure the quality of hole processing at high productivity. The article presents the original universal two-circuit scheme of automatic control of technological processes of drilling and reaming holes. The system controls the technological processes of drilling holes by switching the appropriate taps in the application of hydraulic power heads and improves the quality of processing and tool life. With the help of General transfer functions and according to the Raus - Hurwitz criterion, its stable operation is achieved both during drilling and deployment. The derived mathematical models make it possible to perform calculations to determine the mass-geometric and regime parameters necessary for the design and creation of automatic systems for controlling the modes of operation of hydraulic power heads.

Research on Chrome Plating Quality of the Internal Surfaces in the Hydraulic Drives with Hydrostatic Guideways

2021 ◽  
Vol 1037 ◽  
pp. 417-422
Author(s):  
Dmitrii V. Ardashev ◽  
Nizami Yusubov ◽  
Leonid V. Shipulin ◽  
Anastasiya Degtyareva-Kashutina
Keyword(s):  
Internal Surface ◽  
Chrome Plating ◽  
Technical Requirements ◽  
Internal Surfaces ◽  
Measurement Results ◽  
Chrome Coating ◽  
Hydraulic Cylinders ◽  
Roundness Deviation ◽  
Coating Hardness

The article presents a study of the characteristics of experimental samples with a chrome coating: the straightness and ovality of the inner surface of the cylinder, as well as the hardness and thickness of the chrome coating. The chrome coating is obtained on a previously developed installation for applying chrome coating on the inner surfaces of hydraulic cylinders of hydraulic drives with hydrostatic guides. The measurement of the geometric characteristics of the internal surface of the samples was carried out, the values ​​of deviations from roundness and deviations from straightness were obtained. A study of the chrome coating was carried out, for this we cut out sectors from the samples, carried out their sample preparation, measured the hardness and took pictures under a microscope, measured the hardness and thickness of the chrome coating. The obtained measurement results: deviation from roundness, deviation from straightness, coating hardness, coating thickness - correspond to the specified technical requirements, the proposed construction of the installation for applying chrome coating to the inner surfaces and the electrolyte composition, selected earlier, are applicable for chrome plating of the inner surfaces.

scholarly journals STRUCTURAL PECULIARITIES OF THE PROCESS OF ELECTROLYTIC CHROMIUM PLATING IN RESTORATION OF WORN PARTS

2018 ◽  
pp. 92-97
Author(s):  
I. M. Kovenskiy ◽  
S. V. Malysh ◽  
V. V. Povetkin
Keyword(s):  
Surface Preparation ◽  
Inhomogeneous Structure ◽  
Band Theory ◽  
Electrolytic Chromium ◽  
Chrome Plating ◽  
Chromium Plating ◽  
Thermal Emf ◽  
Structural Peculiarities ◽  
Similarity Of Processes

Processes occurring at the metal-electrolyte interface in chrome plating of parts with an inhomogeneous structure have been considered from the standpoint of the band theory of semiconductors. Similarity of processes in the systems metal - semiconductor and metal - electrolyte has been established. A technique for estimating the quality of surface preparation of worn parts for electrolytic chromium plating based on the results of measuring the spread of thermal EMF values has been validated.

Study of Hard Chromium Plating from Trivalent Chromium Electrolyte

2008 ◽  
Vol 373-374 ◽  
pp. 200-203 ◽  
Author(s):  
Bao Song Li ◽  
An Lin
Keyword(s):  
Wear Resistance ◽  
Hexavalent Chromium ◽  
Amorphous Structure ◽  
Trivalent Chromium ◽  
Functional Coatings ◽  
Complex Ions ◽  
Plating Bath ◽  
Hard Chromium ◽  
Chromium Plating ◽  
Polynuclear Coordination Compounds

Hard chromium deposits were prepared from a trivalent chromium plating bath as an alternative to conventional hexavalent chromium deposits. The influences of bath composition on the trivalent chromium electrodeposition process and deposited coating properties were studied. The effects of plating parameters such as current density, bath pH and plating time on structure and morphology of deposited coatings were investigated. Results show that the hard chromium deposits exhibited amorphous structure with thickness of 50-100μm and acceptable quality for functional coatings. The hard chromium deposits exhibited better wear resistance as well as corrosion resistance than that of hexavalent chromium deposits. The hardness of as-deposited chromium coatings is about 600-700HV. Heat treatment could improve the wear resistance and hardness of the hard chromium deposits. The formation of polynuclear coordination compounds from hydroxyl complex ions at high pH is the main disadvantageous factor for the sustained trivalent chromium plating process.

Criteria for evaluation of the coordinate measurements quality of parts geometric parameters at pilot-experimental production

2019 ◽  
pp. 3-8
Author(s):  
N.Yu. Bobrovskaya ◽  
M.F. Danilov
Keyword(s):  
Quality Indicators ◽  
Quality Management System ◽  
Technical Specification ◽  
Experimental Production ◽  
Technological Heredity ◽  
Coordinate Measurements ◽  
Reasonable Choice ◽  
The Stability ◽  
Geometric Elements

The criteria of the coordinate measurements quality at pilot-experimental production based on contemporary methods of quality management system and traditional methods of the measurements quality in Metrology are considered. As an additional criterion for quality of measurements, their duration is proposed. Analyzing the problem of assessing the quality of measurements, the authors pay particular attention to the role of technological heredity in the analysis of the sources of uncertainty of coordinate measurements, including not only the process of manufacturing the part, but all stages of the development of design and technological documentation. Along with such criteria as the degree of confidence in the results of measurements; the accuracy, convergence, reproducibility and speed of the results must take into account the correctness of technical specification, and such characteristics of the shape of the geometric elements to be controlled, such as flatness, roundness, cylindrical. It is noted that one of the main methods to reduce the uncertainty of coordinate measurements is to reduce the uncertainty in the initial data and measurement conditions, as well as to increase the stability of the tasks due to the reasonable choice of the basic geometric elements (measuring bases) of the part. A prerequisite for obtaining reliable quality indicators is a quantitative assessment of the conditions and organization of the measurement process. To plan and normalize the time of measurements, the authors propose to use analytical formulas, on the basis of which it is possible to perform quantitative analysis and optimization of quality indicators, including the speed of measurements.

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