Theoretical Analysis of Chroming Electrolytes and Properties of Chrome Coatings

2020 ◽  
Vol 836 ◽  
pp. 142-150
Author(s):  
Yu.A. Stekolnikov ◽  
S.D. Polischuk ◽  
D.G. Churilov ◽  
N.V. Byshov ◽  
S.N. Borychev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Deposition Rate ◽  
Transition Time ◽  
Internal Stresses ◽  
High Deposition Rate ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Current Output ◽  
Low Concentration

According to the dynamic characteristics of the electrochemical system, according to V.F. Molchanov, it is possible to optimize the composition of chroming electrolyte and predict the properties of chromium deposits depending on the mode of deposition and the transition time. The possibility of using the transition time for the formation of the cathode surface colloid-dispersion film to study the chemical composition of the chroming solution is considered. The chemical composition can be optimized by the position of the maxima and minima on the polarization curves. An electrochemical cell can be described as a system by a differential equation, the form of which is determined by its internal structure, which varies with electrolysis conditions. The properties of the system are evaluated by a number of factors: the time of the transition process, forcing, attenuation, and the quality factor. This approach is used to develop a low-concentration chroming electrolyte with organic additives. Analytical dependences of chromium yield on current, micro hardness, roughness and deposition rate on deposition conditions are obtained. Chroming on non-stationary modes allows the most effective influence on the structure and physical-mechanical properties of coatings. When changing electrolysis parameters, it is possible to influence the structure and physical-mechanical properties of coatings, to obtain various functional chromium coatings with specified characteristics (adjustable micro hardness in thickness, porosity, internal stresses, corrosion resistance, wear resistance, roughness) from a single electrolyte. The use of a low-concentration electrolyte together with non-stationary deposition modes makes possible to increase the chromium current yield, covering and dissipative ability of the electrolyte, deposition rate, producibility and environmental friendliness of the process, and to reduce hydrogenation. The electrolyte with crystal violet additives has an increased current output (up to 28 %), an extended range of obtaining wear-resistant coatings up to 240 A / dm2, a high deposition rate of up to 2.5 μm / min, an increased micro hardness by 100-300 kg / mm2, reduced toxicity, a decreased absorbed hydrogen level at 500-700 cm3 per 100 grams of chrome coating and internal stresses at 600-950 kg / mm2.

Influence of Substrate Temperature and Bias Voltage on Structure and Mechanical Properties of CrN Coatings

2013 ◽  
Vol 591 ◽  
pp. 99-103 ◽  
Author(s):  
Hao Zhang ◽  
Shu Wang Duo ◽  
Xiang Min Xu ◽  
Huan Ke ◽  
Ting Zhi Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Substrate Temperature ◽  
Deposition Rate ◽  
Bias Voltage ◽  
High Deposition Rate ◽  
Properties Of Coatings ◽  
Unbalanced Magnetron ◽  
Magnetron Sputter ◽  
Influence Of Substrate ◽  
Crn Coatings

CrN coatings have been deposited successfully by Closed Filed Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The effect of substrate temperature (TS) and bias voltage (VB) together on microstructure, morphologies and mechanical properties of CrN coatings were studied. The results showed that the deposition rate of CrN coatings declines with the increase of VB Under both room temperature (R.M.) and 300°C. The FCC-CrN disappeared gradually and orth-CrN arised with the increase of VB, and the TS promoted the transformation from FCC - CrN to orth - CrN. The surface morphology of CrN coatings with changed VBs was greatly different, and VB could further improve the mechanical properties of coatings. In this paper, the CrN coating with the parameters (TS =300°C, VB =-30V) had relatively high deposition rate and mechanical properties.

scholarly journals Application of the plasticity characteristic determined by the indentation technique for evaluation of mechanical properties of coatings: I. specific features of the test method procedure

2004 ◽  
Vol 36 (1) ◽  
pp. 27-41 ◽  
Author(s):  
A.V. Byakova ◽  
Yu.V. Milman ◽  
A.A. Vlasov
Keyword(s):  
Mechanical Properties ◽  
Indentation Load ◽  
Test Method ◽  
Simplified Model ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Modified Model ◽  
Plasticity Characteristic ◽  
Measurement Results ◽  
Hardness Values

Specific features of the test method procedure capable for determining the plasticity characteristic dH by indentation of inhomogeneous coatings affected by residual stress was clarified. When the value of the plasticity characteristic for coating was found to be as great as dH > 0.5 a simplified model was found to be reasonably adequate, while a modified model assumed compressibility of the deformation core beneath indentation. The advantage of the modified approach compared to the simplified one was grounded experimentally only if the elastic deformation for coating becomes greater than ?e ? 3.5%, resulting in the decrease of plasticity characteristic dH < 0.5. To overcome non accuracy caused by the effect of the scale factor on measurement results a comparison of different coatings was suggested using stabilized values of the plasticity characteristic dH determined under loads higher than critical, P ? Pc, ensuring week dependence of micro hardness values on the indentation load.

Chemical Composition and Mechanical Properties of Coatings Based on TiN Formed Using a Condensation with Ion Bombardment

2020 ◽  
Vol 56 (3) ◽  
pp. 539-548
Author(s):  
P. M. Korusenko ◽  
S. N. Nesov ◽  
S. N. Povoroznyuk ◽  
P. V. Orlov ◽  
D. N. Korotaev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Ion Bombardment ◽  
Properties Of Coatings

scholarly journals Performance of MoS2/Zr Composite Coatings at Different Deposition Temperatures

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5100
Author(s):  
Wenlong Song ◽  
Kai Sun ◽  
Guangming Zhao ◽  
Long Zhu ◽  
Shoujun Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Deposition Temperature ◽  
Adhesion Force ◽  
Composite Coatings ◽  
Hardened Steel ◽  
Dry Sliding ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Mechanical And Tribological Properties ◽  
Deposition Technology

The properties of the MoS2/Zr coatings can be significantly affected by the deposition temperature. In this study, the MoS2/Zr composite coatings were fabricated on the cemented carbide surface, utilizing the duplex deposition technology at various deposition temperatures. The effects of deposition temperature on the mechanical and friction properties of the MoS2/Zr coatings were systematically studied. Results exhibited that as the deposition temperature increased, the adhesion force increased first and then decreased, and the coating thickness and micro-hardness gradually increased. Dry sliding tests against a hardened steel ring showed that the tribological behaviors and wear mechanisms of the MoS2/Zr coatings varied with deposition temperature, which were due to the changing mechanical properties of coatings caused by the temperature. The coatings deposited at a temperature of 180 °C and 200 °C possessed preferable comprehensive mechanical and tribological properties.

Evaluation and comparison the effect of heat treatment on mechanical properties of NiCrBSi thermally sprayed coatings

2018 ◽  
Vol 65 (1) ◽  
pp. 34-37
Author(s):  
Mohsen Shabanlo ◽  
Reza Amini Najafabadi ◽  
Amirhossein Meysami
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Test ◽  
Flame Spray ◽  
Micro Hardness ◽  
Post Heat Treatment ◽  
Properties Of Coatings ◽  
Content Type ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

Purpose This study aims to investigate the effect of post heat treatment on mechanical properties of NiCrBSi coatings, which were applied on 316L stainless steel using high-velocity oxygen-fuel (HVOF) and flame spray techniques. Design/methodology/approach The properties of coatings were investigated by metallographic characterizations as well as wear, micro-hardness and adhesion tests. Findings The micro-hardness results showed that the coatings considerably increased the sub-layer hardness. In addition, regarding the wear test results, it can be seen that heat treatment increased wear resistance of the coatings. These thermal sprayed coatings are usually re-melted by post heat treatment, leading to improvement in tribological properties. The results obtained revealed that re-melting procedure improved the metallurgical bonding in the substrate\coating interface. Originality/value Microstructure defects resulting from thermal spraying such as pores and unmelted particles can be eliminated by post heat treatment. This process can considerably improve the corrosion and wear resistances of the thermal sprayed coatings.

Surface Modification of Silicon Nano Mechanical Structures by Carbon Ion Implantation for Post-fabrication Transformation to Silicon Carbide

2005 ◽  
Vol 908 ◽  
Author(s):  
Kumar R Virwani ◽  
Dinesh K Sood ◽  
Robert G Elliman ◽  
Ajay P Malshe
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Surface Modification ◽  
Chemical Composition ◽  
Ion Implantation ◽  
Bending Strength ◽  
Internal Stresses ◽  
Carbon Ions ◽  
Carbon Ion ◽  
Unique Ability

AbstractInternal stresses can cause de-lamination and fracture of coatings and structures and it is well known that ion-implantation can be used to control such behavior through modification of the stress. Here, however, we show that the unique ability of implantation to create controlled stresses in materials by altering both the chemical composition and mechanical properties, combined with an increase in the bending strength of materials, can used to create novel vertical nanostructures. Silicon cantilevers (beams), 193nm thick, 200nm wide and 3μm long, were implanted with carbon ions to create a buried SiCx layers. The internal stresses generated by implantation caused the beams to bend at angles ranging from 10 degrees to greater than 90 degrees, leading to unique vertical nanostructures. This method can be used to create 3-D nano electromechanical systems (NEMS).

scholarly journals THE POLYPROPYLENE BIPOLAR ELECTRODE FOR COBALT ELECTROEXTRACTION

2020 ◽  
Vol 1 (46) ◽  
pp. 218-225
Author(s):  
Melnik N ◽  
◽  
Vlasenko N ◽  
Kovalenko I ◽  
Shpak A ◽  
...  
Keyword(s):  
Heavy Metal Ions ◽  
Measuring Method ◽  
High Energy ◽  
Metal Extraction ◽  
Bipolar Electrode ◽  
Energy Costs ◽  
Micro Hardness ◽  
Concentrated Solutions ◽  
Current Output ◽  
Low Concentration

In the article the polypropylene bipolar electrode is offered for the cobalt extraction from low concentration solutions. Research object: electrolyzer with polypropylene bipolar electrode. Purpose of the study: research of cobalt electroextracton on the polypropylene bipolar electrode from low concentrated solutions. Research methods: stationary and non-stationary voltamperometry. measuring method of micro hardness. It was established that application of bipolar electrolyzer provides high purity electro-extraction of metal in the process of cobalt extraction. Using of polypropylene bipolar electrode provides lightness and plasticity that is not realized in the case of similar metallic. Received fallouts have a microhardness from 350 to 450 kg/мм2, depending on ions concentration of metal in electrolyte. Fallouts with maximal microhardness - homogeneous, fine crystalline with narrow distribution after the sizes of 5 - 8 mkm. The maximal values of extraction coefficient and current output from diluted solutions of their salts set 74 аЫ 76 % (respectively) at the rate of bipolar movement 1,5 спі/miin For an extraction 1 kg of cobalt it is necessary 20 kW4i, the process is effective and does not require high energy costs. The results of the article can be implemented in technology of wastewater treatment from heavy metal ions at galvanic productions. In the future it is planned to study the possibility of application polypropylene bipolar electrode for metal extraction. KEY WORDS: POLYPROPYLENE BIPOLAR ELECTRODE, COBALT ELECTOEXTRACTION, LOW CONCENTRATION SOLUTIONS.

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