Zastita materijala最新文献

{"title":"Calculation of a pure double-layer capacitance from a constant phase element in the impedance measurements","authors":"V. Jović","doi":"10.5937/zasmat2201050j","DOIUrl":"https://doi.org/10.5937/zasmat2201050j","url":null,"abstract":"Considering literature of electrochemical impedance spectroscopy (EIS) it was discovered that for calculation of the value of double-layer capacitance (Cdl) from the constant phase element (CPE) two equations, with or without solution resistance (Rs) could be used. After calculation of Cdl for defined values of CPE constant Ydl, CPE exponent , Rs and charge transfer resistance (Rct), it was confirmed in this work that different results for Cdl were obtained by including Rs in the calculation of Cdl. It was also stated that \"it is quite difficult to understand how both parameters (Rct and Rs) could be expressed by the same time constant, i.e. the same parameter .\" By investigating the hydrogen evolution reaction (HER) at Ni mesh 40 electrode in the solution of 1 M KOH at 25 oC using EIS measurements, it was shown that different Cdl vs. E plots were obtained using these two equations for Cdl calculation. A simple solution to avoid this problem with detailed explanation, the use of equation without Rs , has been suggested in this work.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86767879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing the effectiveness of raspberry flower extract as an inhibitor of copper's corrosion in 3% NaCl","authors":"Dejana Kasapović, F. Korać, F. Bikić","doi":"10.5937/zasmat2202115k","DOIUrl":"https://doi.org/10.5937/zasmat2202115k","url":null,"abstract":"The paper presents an examination of the possibility of applying raspberry flower extract (Rubus idaeus L.) as a green inhibitor of general corrosion of copper in 3% NaCl. Raspberry flowers (Rubus idaeus L.) sort Polka were collected from the Moševac near Maglaj city, Bosnia and Herzegovina. Raspberry flower extract in ethanol was obtained by ultrasonic extraction. A significant content of polyphenol was found in the raspberry flower extract by UV/VIS spectrophotometry analysis. Results obtained by DC techniques (by the methods of Tafel extrapolation, potentiodynamic polarization and linear polarization) prove that the corrosion rate decreases in the presence of the raspberry flower extract. Tests performed by the method of electrochemical impedance spectroscopy prove that the tested extracts slow down the kinetics of the corrosion process, which is visible through the increase in resistance. The results of the conducted tests prove that in an aggressive medium, such as 3% NaCl solution, Polka raspberry flower extract can be used as an inhibitor of copper's corrosion.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79651794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of thiourea on the corrosion resistance of mild steel immersed in simulated concrete pore solution","authors":"P. Shanthy, K. Kavipriya, B. Santhiya, Ganesan Priyanka, K. Vigneswari, V. Velkannan, Gurmeet Singh, A. Al-Hashem, A. Nilavan, S. Rajendran, Č. Lačnjevac","doi":"10.5937/zasmat2204447s","DOIUrl":"https://doi.org/10.5937/zasmat2204447s","url":null,"abstract":"The corrosion resistance of mild steel in simulated concrete pore solution (SCPS) in the absence and presence of thiourea has been investigated by polarization study and AC impedance spectra. Polarisation study reveals that thiourea system functions as anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. When mild steel is used as rebar, thiourea may be mixed with concrete. Thus the mild steel will be protected from corrosion. The protective film consists of iron-thiourea complex formed on metal surface. In the presence of thiourea the linear polarisation resistance increases, corrosion current decreases, charge transfer resistance (Rt) increases, impedance increases, phase angle increases and double layer capacitance (Cdl) value decreases. This formulation may find application in concrete technology.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91139537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adsorption and inhibitive impact of 5-[4-(dimethylamino) benzylidene]-1,3-dimethylbarbituric acid on carbon steel corrosion in molar hydrochloric acid solution","authors":"El-Khalek Abdel, K. Shalabi, M. Ismail, E. Fouda","doi":"10.5937/zasmat2203238a","DOIUrl":"https://doi.org/10.5937/zasmat2203238a","url":null,"abstract":"The inhibiting impact of ecofriendly 5-[4-(dimethylamino) benzylidene]-1,3-dimethylbarbituric acid in 1 M HCl on the corrosion for carbon steel has been examined via \"weight loss (WL) method, potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) tests\". The attained outcomes exhibit that the investigated compound is excellent inhibitor and its inhibition efficiency (%IE) rises by raising concentration and decreases by raising the temperature. The adsorption of 5-arylidene barbituric acid on the surface of C-steel follows Langmuir isotherm. The adsorption process of the investigated compound is spontaneous and considered as of chemisorption and physisorption type. PP curves revealed that the 5-arylidene barbituric acid derivative is mixed-type inhibitor. Moreover, EIS results confirmed the adsorption of the investigated compound on C-steel surface via increasing on charge transfer resistance (R ct). The IE% of this inhibitor reached to 86.9% at concentration 21×10-6 M according to PP method. Finally, the experimental and theoretical results are in good harmony.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74107921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Binders for pressed products based on phosphogypsum waste","authors":"L. Dvorkin, O. Bordiuzhenko","doi":"10.5937/zasmat2204437d","DOIUrl":"https://doi.org/10.5937/zasmat2204437d","url":null,"abstract":"The article is devoted to the issues of obtaining pressed building materials based on dihydrate phosphogypsum. Dihydrate phosphogypsum after mechanical activation in a ball mill acquires the ability to harden in pressed specimens. After activation of dihydrate phosphogypsum in a ball mill and its pressing at a pressure of 30 MPa, the strength of specimens increases by 6...8 times compared to non-activated specimens and reaches 25...30 MPa. There is found the influence of various chemical admixtures on binding properties of activated phosphogypsum and there are shown possibilities of water resistance improvement and increasing of other properties characterizing this material. There is studied an effect of aggregates on the building and technical properties of artificial stone made of phosphogypsum and peculiarities of its structure and change under the influence of different factors.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72375647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning-based underwater metal object detection using input image data and corrosion protection of mild steel used in underwater study: A case study: Part A: Deep learning-based underwater metal object detection using input image data","authors":"Dorothy Rajendran, T. Sasilatha, D. Amala, Rajendran Santhammal, Č. Lačnjevac, Gurmeet Singh","doi":"10.5937/zasmat2201005r","DOIUrl":"https://doi.org/10.5937/zasmat2201005r","url":null,"abstract":"Due to the importance of underwater exploration in the development and utilization of deep-sea resources, underwater autonomous operation is more and more important to avoid the dangerous high-pressure deep-sea environment. For underwater autonomous operation, intelligent computer vision is the most important technology. In an underwater environment, weak illumination and low-quality image enhancement, as a pre-processing procedure, is necessary for underwater vision. In this paper, introduced Deep learning-based Underwater Metal object detection using input Image data by using several step to improve the model performance. In this experimentation we are using TURBID dataset 100 images to validate the performance. And also we compare the performance result by given the input images in different validation level. In first input image is initially preprocessed and that images is given to the KFCM-Segmentation. The segmented images are given to the DWT Extraction to extract the features from those images. And finally the Convolution Neural Network (CNN) is used to classify the images to detect the objects. Also this proposed model attained the classification accuracy of 98.83%. This method is much suitable for detect the objects in underwater robotically. Metallic parts of machines of ships or airplanes may submerge in sea water. They may undergo corrosion when they come in contact with sea water which contains 3.5% sodium chloride. This is most commonly responsible for the corrosive nature of the seawater. The robots made of materials such as mild steel may also undergo corrosion when they come in contact with sea water, while is search. If a paint coating is given, it will control the corrosion of these proposed materials. Hence this work is undertaken. Mild steel is coated with Asian guard red paint. Corrosion resistance of mild in 3.5% sodium chloride solution is measured before coating and after coating by electrochemical studies such as polarization study and AC impedance spectra. The corrosion inhibition efficiency offered by red paint to mild steel in 3.5% sodium chloride is 99.98%.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80190100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical studies on the corrosion behaviour of Aluminium in an alkaline medium","authors":"P. Satyabama, Nellainayagam Narendran, K. Devi, Thiruppathi Sankareswar, A. Nilavan, S. Rajendran, Č. Lačnjevac","doi":"10.5937/zasmat2203230s","DOIUrl":"https://doi.org/10.5937/zasmat2203230s","url":null,"abstract":"Corrosion of Aluminum metal at pH 10 has been controlled by dicarboxylic acids such as oxalic acid (OA) and adipic acid (AA).The Inhibition efficiency (IE) has been determined by the classical weight loss method. The maximum inhibition efficiency (IE) offered by the oxalic acid (OA) and adipic acid (AA) 250 ppm and Zn2+ 50 ppm system are 88 and 96%. To determine the values of Linear Polarization Resistance (LPR) and corrosion Current (Icorr), potentiodynamic polarization study has been used.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80587083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of amino acids used as corrosion inhibitors on iron metal/alloys in aggressive environments","authors":"Ifeyinwa Ekeke, S. Efe, F. Nwadire","doi":"10.5937/zasmat2203318e","DOIUrl":"https://doi.org/10.5937/zasmat2203318e","url":null,"abstract":"Research into the use of safe and environmentally friendly corrosion inhibitors can pave the way for an understanding of their inhibition mechanisms in metallic alloy materials. This review seeks to present and discuss the research work reported in the literature on the use of amino acids and their derivatives as corrosion inhibitors for iron and its alloys in different aggressive solutions. This non-toxic, biodegradable and relatively cheap corrosion inhibitor has shown to be efficient as an inhibitor for metals/alloys in acidic, alkaline and neutral solutions depending on experimental conditions. Electrochemical and surface techniques were among the most often used techniques to evaluate the corrosion inhibition efficiency of amino acids. Highest values of inhibition efficiency can be obtained in the presence of ions as Iand Br. This review presents and discusses most of the contributions made in literature on the use of amino acids and their derivatives as corrosion inhibitors for iron and its alloys.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80442988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on mechanical properties of Inconel 625 and Incoloy 800H with nitrate based molten salts","authors":"Hariharan Kamatchi, A. Anderson, K. Suresh","doi":"10.5937/zasmat2204477h","DOIUrl":"https://doi.org/10.5937/zasmat2204477h","url":null,"abstract":"Energy storage is the most indispensable technology in the recent days with augmented power demand, which helps in balancing the energy demand and production time. Among the broad spread of energy storage types, molten salts technology in concentrated solar plants is most economical, highly efficient with excellent duration on the storage timings. In this current effort, Inconel 625 and Incoloy 800H nickel based super alloys have been taken and heated with sodium nitrate and potassium nitrate molten salts. The super alloy substrates were coated with Yttria stabilized zirconia as thermal barrier coating which could enhances the heat resistance and corrosion resistance property of the base substrates. Both layered and non-coated super alloy samples were intense to a fairly accurate temperature of 1000 o C for different duration as 9, 12 and 15 hours. The mechanical properties of both unheated and heated specimens were compared with the results obtained from tensile test, compression test, hardness test, and impact test. The changes in the micro-structural properties were investigated with the support of SEM images and by XRD analysis. The mechanical properties of YSZ coated specimens are found to be better than the uncoated specimens; which increases the sustainability of the super alloys with the molten salts.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82564671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disorders of magnesium alloy injection molding","authors":"O. Myronova, V. Goryany","doi":"10.5937/zasmat2201079m","DOIUrl":"https://doi.org/10.5937/zasmat2201079m","url":null,"abstract":"The feed problems in the injection molding of different magnesium alloys were investigated and explained. The examinations carried out with magnesium alloys AZ91D, ZC63 and MRI230D have shown that in addition to the known causes, other factors can also affect the draw-in disturbance. Those are following: a contaminated granulate, the unevenness and size of fine particles, a low melting eutectic and the bevels that are used to reinforce magnesium alloys. The causes of disturbance factors that occur were analyzed and solutions were developed to eliminate and avoid them.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82721049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}