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Peculiarities of chromium deposition process using inductance-capacitor device


Author: Ivaşcu Sergiu
Degree:doctor of engineering
Speciality: 02.00.05 - Electrochemistry
Year:2012
Scientific advisers: Viorel Gologan
doctor habilitat, professor, Institute of Applied Physics, Academy of Sciences of Moldova
Jana Bobanova
doctor
Institution: Institute of Applied Physics, Academy of Sciences of Moldova

Status

The thesis was presented on the 1 November, 2012
Approved by NCAA on the 20 December, 2012

Abstract

Adobe PDF document1.76 Mb / in romanian

Keywords

Chromium, electrodeposition, inductive-capacitive device, inductance, capacitance, polarization, power yield, spectrum, variable components of current, morphology, structure, resistance to wear

Summary

The thesis includes Introduction, 4 Chapters, General conclusions and recommendations, List of references from 162 bibliographic sources, 6 Annexes, 127 pages of the main text, 42 figures and 10 tables. The results are published in 24 scientific papers, and protected by three patents.

Area of study: electrochemistry.

The purpose and main objectives of research: improving the process of chromium using inductively-capacitance device (ICD), determine the degree of influence of the parameters ICD (L, C) on the deposition process and properties of the coatings and the feasibility of these devices is the deposition of chromium and other coatings.

Scientific novelty and originality of research. First established: the influence of parameters on the polarization of the electrode ICD and range of the variable components, with a more positive potential of the cathode (Lop, Cop) increases the current output, structure of the coating becomes more uniform with smaller units, with Lop, Cop had more wear resistant coatings obtained by iК = 8.5kA/m2 that provides an increase in deposition rate of precipitation from 30 to 82 microns/hour. It is shown that changing the conditions of electrolysis, it is possible to obtain new materials (patent MD 4031 C1 2010.04.30).

The theoretical significance. We confirmed the hypothesis of the possibility of galvanic process control parameters change inductance-capacitance devices. It is assumed that the increase in current efficiency is due to the change in thickness and structure of the colloidal film, which facilitates the diffusion process. Deposition of coatings with a homogeneous structure and smaller aggregates seem to be caused by the diffusion changes that help to increase the number of crystallization centers. The increase of microhardness and wear resistance of coatings suggests a heightened role of the border units in the process of deformation and fracture of deposition.

Implementation of scientific results. Recommendations of the thesis can be realized by designing and implementing processes for chrome car parts, which increases the deposition rate of 2,5 times the wear resistance of coatings to 2 times in optimal conditions of electrolysis (iК = 8.5kA/m2, L = 0,119mH, C = 0,024F), which provides economic benefits to the 1500 lei per 1m2. We propose a new ICD (patent MD3573 C2 2008.04.30) and single-phase source (patent MD 3517 G2 2008.02.29).