Nanosecond laser cleaning for enhanced zinc coating quality of HSLA steel

Zinc sulfate is the main component in the composition of the acidic zinc plating electrolyte. Deviation in the electrolyte composition from the optimum content leads to destabilization of the electrolysis process and deteriorate the quality of the resulting zinc coating. The proper quality of a zinc coating obtained by galvanic deposition can be ensured only with timely monitoring and adjustment of the electrolyte composition. A technique of X-ray fluorescence determination of zinc (in terms of zinc sulfate) in an acidic zinc plating electrolyte is proposed. The study was carried out using an ARL Quant’X energy dispersive spectrometer (Thermo Fisher Scientific, USA) with a semiconductor silicon-lithium detector. The features of the spectrometer design are presented. The optimal parameters of excitation and detection of zinc radiation were specified when the electrolyte sample was diluted 1:1000. The ZnKα1 line was used as an analytical line. The plotted calibration graph is linear, the correlation coefficient being 0.999234. The results of zinc determination according to the developed method were compared with the data of the reference method of complexometric titration to prove the reliability of the procedure. The results are characterized by good convergence and accuracy. The proposed method of X-ray fluorescence zinc determination in a zinc plating electrolyte equals complexometric titration in the limiting capabilities and even exceeds the latter in terms of the simplicity of sample preparation and rapidity. The developed method of X-ray fluorescence determination of zinc is implemented in analysis of the electrolyte used in the continuous galvanizing unit at «METSERVIS LLC».

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Simulation of nanosecond laser cleaning the paint based on the thermal stress

Optik ◽

10.1016/j.ijleo.2020.165589 ◽

2021 ◽

Vol 227 ◽

pp. 165589

Author(s):

Yao Lu ◽

LiJun Yang ◽

MaoLu Wang ◽

Yang Wang

Keyword(s):

Thermal Stress ◽

Laser Cleaning ◽

Nanosecond Laser

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Improving the Quality of the Coating at Hot-Dip Galvanizing of Machine Steels in the Zinc Melt with Microadditives of Nickel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.685.380 ◽

2016 ◽

Vol 685 ◽

pp. 380-384 ◽

Cited By ~ 1

Author(s):

Olga S. Bondareva ◽

Alexey A. Melnikov

Keyword(s):

Elemental Composition ◽

Zinc Coating ◽

Ternary Diagram ◽

Nickel Concentration ◽

Mechanism Of Formation

The technology of microalloying zinc melt by nickel is widely used to control the thickness of the zinc coating when the machine steels are subject to hot-dip galvanization. However, in some cases inclusions of Ni-Zn-Fe dross are formed on surface of the products, which leads to their deterioration. The aim of this work is to investigate the microstructure, mechanism of formation and elemental composition of this dross. Conditions for the formation of different phases in the coating were analyzed using Ni-Zn-Fe ternary diagram. It was found that Ni-Zn-Fe dross is a ζ-phase containing about 0.5 at. % nickel and isomorphic with FeZn13-phase. The main reasons for the formation of Ni-Zn-Fe dross are Zn-Fe contamination in the melt, the excess nickel concentration (more than 0.06 at.%), and the irregular nickel concentration in the melt. Methods for preventing this type of defects in hot-dip galvanization have been proposed.

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Study on Surface Quality of Wood Processed by Water-jet Assisted Nanosecond Laser

BioResources ◽

10.15376/biores.13.2.3125-3134 ◽

2018 ◽

Vol 13 (2) ◽

Cited By ~ 2

Author(s):

Chunmei Yang ◽

Ting Jiang ◽

Yueqiang Yu ◽

Guoqiang Dun ◽

Yan Ma ◽

...

Keyword(s):

Surface Quality ◽

Water Jet ◽

Nanosecond Laser

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Corrosion resistance of zinc-based systems in NaCl environment

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun201361051487 ◽

2013 ◽

Vol 61 (5) ◽

pp. 1487-1495 ◽

Cited By ~ 2

Author(s):

Jiří Votava

Keyword(s):

Corrosion Resistance ◽

Salt Spray ◽

Current Trend ◽

Zinc Coating ◽

Degradation Process ◽

Engineering Industry ◽

Anticorrosion Protection ◽

Al Coating ◽

Measurement Of Thickness

Metal components in engineering, industry and agriculture are subjects of degradation process influenced by corrosion which result in changes of mechanical characteristics. The current trend of anticorrosion protection is aimed at inorganic metal zinc-based coatings, such as zinc dipping which can be improved by duplex protection. This paper deals with two types of corrosion protection of steel components by zinc coating, first of which is produced by hot dip galvanizing, the other by Zn-Al spray. Hot dip galvanizing was processed in working conditions; the Zn-Al coating was sprayed following the instructions of producer. It is a special aerosol with particles of Zn and Al sized approximately 5 µm. There have been processed the following tests: analysis of element structure, test of corrosion resistance in aggressive environment of salt spray according to ČSN ISO 9227, further measurement weight of applied coatings according to ČSN EN ISO 3892 and measurement of thickness of passivating coating. There was also made an analysis of coating tenacity on bending pin according to ČSN EN ISO 8401. Quality of applied coatings was evaluated following the metallographic scratch pattern.

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THE INFLUENCE OF INTERSTITIAL IMPURITIES IN THE Zr–Y TARGET ALLOYS ON THE HEAT RESISTING CERAMIC COATING QUALITY

Proceedings of VIAM ◽

10.18577/2307-6046-2021-0-2-52-61 ◽

2021 ◽

pp. 52-61

Author(s):

S.P. Konokotin ◽

◽

R.M. Nazarkin ◽

Keyword(s):

High Temperatures ◽

Ceramic Coating ◽

Chemical Deposition ◽

Thermal Barrier ◽

Coating Process ◽

Plasma Chemical ◽

Coating Quality ◽

Interstitial Impurities ◽

Argon Ions

The influence of interstitial impurities in the Zr–Y target alloys (manufactured by two different techniques) on the quality of thermal barrier ceramic layers of heat resisting coating are studied in this work. The heat resisting ceramic coating manufactured in the UOKS-2 devices by magnetron medium-feculence plasma–chemical deposition on the surface of components that are used at the high temperatures (above 1150 °C). It was found that when the content of interstitial impurities in the target alloy is more than 0,1% (1000 ppm), the rate of the coating process decreases and has to be maintained by increasing the energy of argon ions. This leads to overheating of the target alloy and the surface of the parts (substrate) which impairs the adhesion of the deposited atoms.

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Investigation on the Surface Properties of 5A12 Aluminum Alloy after Nd: YAG Laser Cleaning

Coatings ◽

10.3390/coatings9090578 ◽

2019 ◽

Vol 9 (9) ◽

pp. 578 ◽

Cited By ~ 3

Author(s):

Guodong Zhu ◽

Shouren Wang ◽

Wei Cheng ◽

Gaoqi Wang ◽

Wentao Liu ◽

...

Keyword(s):

Corrosion Resistance ◽

Aluminum Alloy ◽

Laser Cleaning ◽

Alloy Surface ◽

Residual Tensile Stress ◽

Yag Laser ◽

Diode Pumped ◽

Aluminum Alloy Surface ◽

Diode Pumped Nd:Yag Laser

The surface of the aluminum alloy is prone to oxidation, which in turn affects the quality of the weld. The 5A12 aluminum alloy was cleaned by acousto-optic Q-switched diode-pumped Nd:YAG laser and the effects of different laser powers and different cleaning speeds on the surface roughness, microstructure, element content, microhardness, residual stress and corrosion resistance of aluminum alloy were investigated. The results show that when the power is 98W and the cleaning speed is 4.1 mm/s, the effect of Nd: YAG laser on the removal of oxide film on 5A12 aluminum alloy surface is the most effective. After laser cleaning, the smoothness and strength of aluminum alloy surface can be effectively improved. However, as a major element in 5A12 aluminum alloy, the content of magnesium decreased. At the same time, the residual tensile stress was generated on the surface of the aluminum alloy after cleaning, and the corrosion resistance slightly decreased.

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Image-Based Artificial Intelligence Methods for Product Control of Tablet Coating Quality

Pharmaceutics ◽

10.3390/pharmaceutics12090877 ◽

2020 ◽

Vol 12 (9) ◽

pp. 877

Author(s):

Cosima Hirschberg ◽

Magnus Edinger ◽

Else Holmfred ◽

Jukka Rantanen ◽

Johan Boetker

Keyword(s):

Classification Model ◽

Computational Time ◽

Support Vector ◽

Coating Quality ◽

Coating Solution ◽

Human Decision ◽

Control Situations ◽

The Individual ◽

Product Control

Mimicking the human decision-making process is challenging. Especially, many process control situations during the manufacturing of pharmaceuticals are based on visual observations and related experience-based actions. The aim of the present work was to investigate the use of image analysis to classify the quality of coated tablets. Tablets with an increasing amount of coating solution were imaged by fast scanning using a conventional office scanner. A segmentation routine was implemented to the images, allowing the extraction of numeric image-based information from individual tablets. The image preprocessing was performed prior to utilization of four different classification techniques for the individual tablet images. The support vector machine (SVM) technique performed superior compared to a convolutional neural network (CNN) in relation to computational time, and this approach was also slightly better at classifying the tablets correctly. The fastest multivariate method was partial least squares (PLS) regression, but this method was hampered by the inferior classification accuracy of the tablets. Finally, it was possible to create a numerical threshold classification model with an accuracy comparable to the SVM approach, so it is evident that there exist multiple valid options for classifying coated tablets.

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