Abderrahim Mokhefi, M. Bouanini, M. Elmir, P. Spitéri
The enhancement of the heat transfer in the stirred tank is a much-desired objective for accelerating certain physical and chemical parameters in the industrial field. From this basis, an attempt is made in this paper to investigate the effect of the wavy wall of a stirred tank on the hydrodynamic, thermal, and energetic behavior of an Al2O3-Water nanofluid. The stirred tank has a flat bottom, and it is equipped with an anchor stirrer. A hot temperature has been imposed on the tank wall, and the agitator has been assumed adiabatic, where the nanofluid has a cold temperature at the initial instant. The laminar flow was governed by the equations that describe the forced convection, and it was solved by the finite element method. The numerical simulation results showed a considerable acceleration in the heat transfer inside the stirred tank by increasing the amplitude of the wavy wall and increasing the nanoparticle concentration. However, there has been a remarkable increase in the stirring power number. This contribution aims to increase thermal efficiency, especially in the chemical and petrochemical fields, to obtain a better yield of certain chemical reactions and mass transfer depending on the heat.
{"title":"Effect of the wavy tank wall on the characteristics of mechanical agitation in the presence of a Al2O3-water nanofluid","authors":"Abderrahim Mokhefi, M. Bouanini, M. Elmir, P. Spitéri","doi":"10.30544/626","DOIUrl":"https://doi.org/10.30544/626","url":null,"abstract":"The enhancement of the heat transfer in the stirred tank is a much-desired objective for accelerating certain physical and chemical parameters in the industrial field. From this basis, an attempt is made in this paper to investigate the effect of the wavy wall of a stirred tank on the hydrodynamic, thermal, and energetic behavior of an Al2O3-Water nanofluid. The stirred tank has a flat bottom, and it is equipped with an anchor stirrer. A hot temperature has been imposed on the tank wall, and the agitator has been assumed adiabatic, where the nanofluid has a cold temperature at the initial instant. The laminar flow was governed by the equations that describe the forced convection, and it was solved by the finite element method. The numerical simulation results showed a considerable acceleration in the heat transfer inside the stirred tank by increasing the amplitude of the wavy wall and increasing the nanoparticle concentration. However, there has been a remarkable increase in the stirring power number. This contribution aims to increase thermal efficiency, especially in the chemical and petrochemical fields, to obtain a better yield of certain chemical reactions and mass transfer depending on the heat.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76970484","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}
The Electron Beam welding (EBW) process was employed to fabricate 18 mm thick fully penetrated butt welds of AISI 321 stainless steel. Nail-shaped weld wide at the top and narrow at the bottom was obtained. Characterization of the weld joint was carried out using optical microscopy, scan electron microscopy, X-ray diffraction, microhardness, impact toughness test, and tensile strength test. The microstructure of the weld metal was found to be free from defects like cracks, porosity, etc. The weld metal consisted of the primarily austenitic matrix with skeletal and vermicular morphology of δ-ferrite by the side of the grain boundaries. Carbides of Cr and Ti were found in the weld metal after the thermal aging treatment of 750 °C for 24 hours, as revealed by the XRD analysis. The tensile strength study revealed a maximum strength of 575 MPa at the root of the weld joint in the as-welded state. The maximum impact toughness of 129.3 J was obtained in the top section of the weld in the as-welded condition. The results in terms of structure-property correlate relationship. This study recommends the effectiveness of EBW for joining 18 mm thick AISI 321.
{"title":"Microstructural characterization and mechanical performance along the thickness of electron beam welded stabilized AISI 321 stainless steel","authors":"Ajay Sharma, V. Prabhakar, S. Sandhu","doi":"10.30544/592","DOIUrl":"https://doi.org/10.30544/592","url":null,"abstract":"The Electron Beam welding (EBW) process was employed to fabricate 18 mm thick fully penetrated butt welds of AISI 321 stainless steel. Nail-shaped weld wide at the top and narrow at the bottom was obtained. Characterization of the weld joint was carried out using optical microscopy, scan electron microscopy, X-ray diffraction, microhardness, impact toughness test, and tensile strength test. The microstructure of the weld metal was found to be free from defects like cracks, porosity, etc. The weld metal consisted of the primarily austenitic matrix with skeletal and vermicular morphology of δ-ferrite by the side of the grain boundaries. Carbides of Cr and Ti were found in the weld metal after the thermal aging treatment of 750 °C for 24 hours, as revealed by the XRD analysis. The tensile strength study revealed a maximum strength of 575 MPa at the root of the weld joint in the as-welded state. The maximum impact toughness of 129.3 J was obtained in the top section of the weld in the as-welded condition. The results in terms of structure-property correlate relationship. This study recommends the effectiveness of EBW for joining 18 mm thick AISI 321.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73217623","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}
The paper investigates the multi response optimization of single bead deposition characteristics which affects the additive manufactured structures in later stages of multi layered depositions. Inconel 625 single beads were deposited using the cold metal transfer (CMT) based on Wire Arc Additive Manufacturing (WAAM). The bead width, bead height, penetration depth as well as microhardness of the fusion region are considered for the decision criteria models. Grey relational analysis (GRA) is used to solve the multi criteria optimization problem. Analysis of variance has been performed to quantify the parameters effects on grey relational grade (GRG). From the GRA, it is observed that at parameter setting of 110 Amps current, 0.4 mm/sec weld speed, and 4 mm standoff distance gives minimum bead width, minimum bead height, maximum penetration depth, and maximum microhardness.
{"title":"Multi response optimization of Inconel 625 wire arc deposition for development of additive manufactured components using Grey relational analysis (GRA)","authors":"Sarath Dongari, M. Davidson","doi":"10.30544/586","DOIUrl":"https://doi.org/10.30544/586","url":null,"abstract":"The paper investigates the multi response optimization of single bead deposition characteristics which affects the additive manufactured structures in later stages of multi layered depositions. Inconel 625 single beads were deposited using the cold metal transfer (CMT) based on Wire Arc Additive Manufacturing (WAAM). The bead width, bead height, penetration depth as well as microhardness of the fusion region are considered for the decision criteria models. Grey relational analysis (GRA) is used to solve the multi criteria optimization problem. Analysis of variance has been performed to quantify the parameters effects on grey relational grade (GRG). From the GRA, it is observed that at parameter setting of 110 Amps current, 0.4 mm/sec weld speed, and 4 mm standoff distance gives minimum bead width, minimum bead height, maximum penetration depth, and maximum microhardness.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"29 17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82937157","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}
MohammadAli Moslemi Petrudi, M. S. Kiasat, Manouchehr Fadavi, Amin Moslemi Petrudi
Ships are always prone to fatigue through high periodic loads, usually caused by waves and changing load conditions. So, fatigue is an important factor in design. One of the reasons for fatigue in welding parts is variable bending loads. In this paper, a specimen of low-carbon steel T-Bar profiles is used, along with plates of the same type of steel that have been welded by the manual electrode welding process. To determine the distribution of static and dynamic forces created by welding, the specimens were subjected to bending (three-point loading) and tensile tests, and finally fatigue tests. The T-Bar Steel profile has more tolerance for fatigue loads than welded. The load T-Bar profile has not failed until the two million cycles, while the welding specimen has failed in about 3×10 cycles. Finally, strong penetrating welds should be used if a stronger welding joint is required.
{"title":"Experimental Study of Fatigue Durability in Bending Effect on Welded Joints in Steel Profiles","authors":"MohammadAli Moslemi Petrudi, M. S. Kiasat, Manouchehr Fadavi, Amin Moslemi Petrudi","doi":"10.30544/554","DOIUrl":"https://doi.org/10.30544/554","url":null,"abstract":"Ships are always prone to fatigue through high periodic loads, usually caused by waves and changing load conditions. So, fatigue is an important factor in design. One of the reasons for fatigue in welding parts is variable bending loads. In this paper, a specimen of low-carbon steel T-Bar profiles is used, along with plates of the same type of steel that have been welded by the manual electrode welding process. To determine the distribution of static and dynamic forces created by welding, the specimens were subjected to bending (three-point loading) and tensile tests, and finally fatigue tests. The T-Bar Steel profile has more tolerance for fatigue loads than welded. The load T-Bar profile has not failed until the two million cycles, while the welding specimen has failed in about 3×10 cycles. Finally, strong penetrating welds should be used if a stronger welding joint is required.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91034852","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}
A. Royani, S. Prifiharni, G. Priyotomo, S. Sundjono
This study investigates the corrosion rate and corrosion behavior of carbon steel pipe at constant condensed fluid from a geothermal power plant. The corrosion rate of the steel was determined by weight loss analysis, whereas the corrosivity of the condensate fluids was measured by a multimeter Hach HQ40d. The morphology of the corrosion products formed was characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and x-ray diffraction (XRD) analysis. Results showed that the corrosion rate in the liquid part of the condensate fluids is constant during the immersion period when water quality parameters are constant. Meanwhile, the corrosion rate of low carbon steel pipe decreases though with the longer exposure period in the condensate fluid. The decrease of metal corrodibility identical to the lower corrosion rate at a longer exposure time due to the protective corrosion layer formed. The corrosion products during immersion tests identified in the corrosion test were uniform with iron oxide in the form of FeO(OH) and Fe2O3*H2O.
{"title":"Corrosion rate and corrosion behaviour analysis of carbon steel pipe at constant condensed fluid","authors":"A. Royani, S. Prifiharni, G. Priyotomo, S. Sundjono","doi":"10.30544/591","DOIUrl":"https://doi.org/10.30544/591","url":null,"abstract":"This study investigates the corrosion rate and corrosion behavior of carbon steel pipe at constant condensed fluid from a geothermal power plant. The corrosion rate of the steel was determined by weight loss analysis, whereas the corrosivity of the condensate fluids was measured by a multimeter Hach HQ40d. The morphology of the corrosion products formed was characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and x-ray diffraction (XRD) analysis. Results showed that the corrosion rate in the liquid part of the condensate fluids is constant during the immersion period when water quality parameters are constant. Meanwhile, the corrosion rate of low carbon steel pipe decreases though with the longer exposure period in the condensate fluid. The decrease of metal corrodibility identical to the lower corrosion rate at a longer exposure time due to the protective corrosion layer formed. The corrosion products during immersion tests identified in the corrosion test were uniform with iron oxide in the form of FeO(OH) and Fe2O3*H2O.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83939743","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}
The performance of the asphalt mix is significantly influenced by the optimum asphalt content (OAC). The asphalt content is responsible for coating the aggregate surface and filling the voids between the aggregate particles. Thus, the aggregate gradation has a significant influence on the required asphalt content. The Marshall design process is the most common method used for estimating the OAC, and this process is called the asphalt mix design. However, this method is time consuming, labor intensive, and its results are subjected to variations. Thus, this paper employs the artificial neural network (ANN) to estimate the OAC from the aggregate gradation for the two most common gradations used in asphalt mixes in Egypt (3D, 4C). Results show that the proposed ANN can predict the OAC with a coefficient of correlation of 0.98 and an average error of 0.026%. As a result, a new approach for the Marshall test can be adopted using results of the proposed ANN, and only three specimens, instead of fifteen, are prepared and tested for estimating the remaining parameters. This approach saves the time, effort, and resources required for estimating the OAC. Additionally, the ANN was validated with previously developed models, and the ANN shows promising results.
{"title":"Prediction of the optimum asphalt content using artificial neural networks","authors":"Kareem Othman, H. Abdelwahab","doi":"10.30544/579","DOIUrl":"https://doi.org/10.30544/579","url":null,"abstract":"The performance of the asphalt mix is significantly influenced by the optimum asphalt content (OAC). The asphalt content is responsible for coating the aggregate surface and filling the voids between the aggregate particles. Thus, the aggregate gradation has a significant influence on the required asphalt content. The Marshall design process is the most common method used for estimating the OAC, and this process is called the asphalt mix design. However, this method is time consuming, labor intensive, and its results are subjected to variations. Thus, this paper employs the artificial neural network (ANN) to estimate the OAC from the aggregate gradation for the two most common gradations used in asphalt mixes in Egypt (3D, 4C). Results show that the proposed ANN can predict the OAC with a coefficient of correlation of 0.98 and an average error of 0.026%. As a result, a new approach for the Marshall test can be adopted using results of the proposed ANN, and only three specimens, instead of fifteen, are prepared and tested for estimating the remaining parameters. This approach saves the time, effort, and resources required for estimating the OAC. Additionally, the ANN was validated with previously developed models, and the ANN shows promising results.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"24 7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89334289","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}
J. Ružić, M. Šimic, N. Stoimenov, D. Božić, J. Stašić
Metal matrix composites (MMCs) belong to a group of modern materials owing to their excellent technological, mechanical, and physical properties such as excellent wear and corrosion resistance, high electrical and thermal conductivity, improved strength and hardness. Final properties of MMCs are affected equally by all steps of its manufacturing process. It is shown that by using adequate process parameters to obtain starting materials (reaching the specific size, shape, and reactivity) the control of volume fraction and distribution of reinforcements within the matrix can be achieved. For this purpose, mechanical alloying has been appointed as a good approach. MMCs can be produced using powder metallurgy, ingot metallurgy, and additive manufacturing techniques. Combining high-energy ball milling with these techniques enables the design of an innovative processing route for MMCs manufacturing. Mechanochemical process (achieved using high-energy ball milling) was employed in three manufacturing procedures: hot pressing, compocasting, and laser melting/sintering for obtaining of the suitable powder. These production routes for MMCs manufacturing were the subject of this work. The aim of MMCs design is to establish an optimal combination of production techniques merged into the cost-effective fabrication route for obtaining MMCs with required properties.
{"title":"Innovative processing routes in manufacturing of metal matrix composite materials","authors":"J. Ružić, M. Šimic, N. Stoimenov, D. Božić, J. Stašić","doi":"10.30544/629","DOIUrl":"https://doi.org/10.30544/629","url":null,"abstract":"Metal matrix composites (MMCs) belong to a group of modern materials owing to their excellent technological, mechanical, and physical properties such as excellent wear and corrosion resistance, high electrical and thermal conductivity, improved strength and hardness. Final properties of MMCs are affected equally by all steps of its manufacturing process. It is shown that by using adequate process parameters to obtain starting materials (reaching the specific size, shape, and reactivity) the control of volume fraction and distribution of reinforcements within the matrix can be achieved. For this purpose, mechanical alloying has been appointed as a good approach. MMCs can be produced using powder metallurgy, ingot metallurgy, and additive manufacturing techniques. Combining high-energy ball milling with these techniques enables the design of an innovative processing route for MMCs manufacturing. Mechanochemical process (achieved using high-energy ball milling) was employed in three manufacturing procedures: hot pressing, compocasting, and laser melting/sintering for obtaining of the suitable powder. These production routes for MMCs manufacturing were the subject of this work. The aim of MMCs design is to establish an optimal combination of production techniques merged into the cost-effective fabrication route for obtaining MMCs with required properties.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"41 1","pages":"1-13"},"PeriodicalIF":0.0,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77099580","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}
This paper describes the influence of deformation by equal-channel angular pressing (ECAP) on the solid particle erosion resistance of the AlSi7Mg0.3 alloy and AlSi7Mg0.3 based composite material reinforced with the addition of 4 % of fly ash (FA) particles. Both, alloy and composite samples were produced using the compo-casting method. The samples have been subjected to ECAP in multiple passes with the rotation of samples around the vertical axis for the angle of 90° after each pass. Particles of silicon carbide (SiC) have been used as erodent while their impact angle was varied (30° and 90°). Observed samples of AlSi7Mg0.3 alloy generally showed higher wear resistance at 90° angle where material fatigue predominates, than at a 30° angle where abrasion-related phenomena predominate. On the other hand, AlSi7Mg0.3 based composite material exhibited erosion wear at 30° angle less than at 90° angle after one ECAP pass. Evaluation of the erosion resistance has been made based on mass and volume loss. After two passes of ECAP, the matrix structure of the AlSi7Mg0.3 based composite material, as well as that of the AlSi7Mg0.3 alloy was improved from the aspect of erosion resistance.
{"title":"Solid particle erosion resistance of Al alloy and Al alloy-fly ash composite subjected to equal-channel angular pressing","authors":"Merima Muslić, V. Rede, V. Maksimović","doi":"10.30544/624","DOIUrl":"https://doi.org/10.30544/624","url":null,"abstract":"This paper describes the influence of deformation by equal-channel angular pressing (ECAP) on the solid particle erosion resistance of the AlSi7Mg0.3 alloy and AlSi7Mg0.3 based composite material reinforced with the addition of 4 % of fly ash (FA) particles. Both, alloy and composite samples were produced using the compo-casting method. The samples have been subjected to ECAP in multiple passes with the rotation of samples around the vertical axis for the angle of 90° after each pass. Particles of silicon carbide (SiC) have been used as erodent while their impact angle was varied (30° and 90°). Observed samples of AlSi7Mg0.3 alloy generally showed higher wear resistance at 90° angle where material fatigue predominates, than at a 30° angle where abrasion-related phenomena predominate. On the other hand, AlSi7Mg0.3 based composite material exhibited erosion wear at 30° angle less than at 90° angle after one ECAP pass. Evaluation of the erosion resistance has been made based on mass and volume loss. After two passes of ECAP, the matrix structure of the AlSi7Mg0.3 based composite material, as well as that of the AlSi7Mg0.3 alloy was improved from the aspect of erosion resistance.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"63 1","pages":"15-26"},"PeriodicalIF":0.0,"publicationDate":"2021-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84509496","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}
This study's main purpose is to achieve an optimal hot-dip coating condition of SnSb for an α-brass alloy. Therefore, the hot-dipping parameters, including pre-flux lubricants, immersion temperature, time, and withdrawal speed were investigated. ZnCl2 and SnCl2 were used as pre-flux bath additives. The temperature of the immersion bath was selected to be in the range of 250-300 °C. Also, the exposing time and withdrawal speed of the specimens during the hot-dipping process were in the range of 10-60 sec and 254-1524 mm/min, respectively. Visual inspection of the coating revealed that by using SnCl2 as a pre-flux additive, high-quality smooth coating is achieved. According to the AFM result, the initial roughness value of the substrate was 450 nm. The coating's roughness value with SnCl2 and SnCl2+ZnCl2 pre-fluxes were in the range of 300-500 and 700-900 nm, respectively. Therefore, ZnCl2 pre-flux is associated with a rougher surface. Corrosion test analysis revealed that both coating condition with different prefluxes leads to increasing corrosion resistance however better improvement in corrosion behavior is accomplished by smooth coating surface. The quantitative analysis of the polarization curve revealed that the corrosion rate of the smooth coating is decreased 712.5 times in comparison with the substrate. According to the SEM analysis, the predominant phases which were appeared at the interface of the coating and substrate were Cu3Sn and Cu6Sn5. SEM analysis revealed that the Cu3Sn intermetallic compound was this first phase, which was promoted near to the substrate vicinity during the hotdipping process. Keyword: α-brass alloy; hot-dipping coating; polarization curve; intermetallic; SEM. Corresponding author: Ali Barak, Alibarak77@gmail.com xxx Metall. Mater. Eng. Vol xx (x) 2021 p. xxx-xxx Introduction Brass alloys (Cu-Zn) have been regarded as commercial alloys. This alloy is one of the familiar candidates for electrical structure, pipe and valve industries due to its excellent thermal and electrical conductivity and appropriate corrosion resistance properties [1-3]. The previous studies demonstrated that the corrosion resistance of the brass alloys is severely dependent on the value of Zinc [4, 5]. As a result of dezincification, the corrosion resistance of the brass alloys was considerably dropped [69]. One practical method for protecting the corrosion behavior of engineering alloys, especially copper base alloy is coating [10]. Among different coating methods, the hotdipped method has been widely developed because of its convenience, time and costsaving issue [11]. The promoted coating has strongly protected the substrate against corrosion. The chemical composition of the coating was selected according to the working and environmental conditions [12]. Kebede et al. [13] reported a list of organic and inorganic inhibitors in order to increase the corrosion resistance of the copper base alloys. Nickel and Tin-Antimony are conventional c
研究参数为:1)预熔剂的化学成分，2)熔池温度，3)浸泡时间，4)试样的提取速度。对促进涂层进行优化后，对合金的腐蚀性能进行了评价。同时，利用SEM和XRD技术对基体(α-黄铜)和涂层(Sn-2.5% Sb)界面的厚度均匀性和出现的相进行了表征。A. Barak等。热浸工艺参数影响的综合研究…α-黄铜合金作为母材，用OES分析确定了其化学成分。结果表明，母材的化学成分为30% Zn70 % Cu。提供尺寸为3×6 cm的试样。试件的初始厚度约为2.5 mm。在制备的第一步，对标本表面进行适当的脱脂处理。为此，样品在70°C的磁铁加热器下的碱溶液中清洗3分钟。碱溶液的化学成分见表1。表1。碱溶液的化学成分。复合NaOH Na2CO3 Na3PO4 Na2SiO3蒸馏废液量6 g 8 g 6 g 10 g 200 ml第二步，通过酸洗工艺将碱溶液组分从样品表面完全清除。因此，标本在100°C下完全干燥，并立即使用HCl (30%) -H2O(70%)溶液进行腌制。尽量缩短酸洗时间，以抑制麻点现象的发生。最后，将标本洗净并在100°C下干燥。在这一步，试样已经准备好进行热浸涂层工艺。本研究将探讨预熔液对涂层质量的影响。在热浸过程中，在熔融浴中加入SnCl2、ZnCl2、NH4Cl等多种润滑剂。实验结果表明，使用SnCl2和ZnCl2润滑剂可以获得合适的涂层。表2报告了所用预熔液的化学成分。熔浴温度选择在250 ~ 320℃，试样热浸暴露时间为254 ~ 1524mm/min，浸出速度为10 ~ 60秒。表2。所用助焊剂的化学成分。预熔槽数助焊剂成分1 12 g ZnCl2+ 80 cc蒸馏水ZnCl2 2 6 g ZnCl2+ 6 g SnCl2+ 80 cc蒸馏水SnCl2+ ZnCl2 3 10 g SnCl2+ 80 cc蒸馏水SnCl2在接下来的步骤中进行热浸镀膜过程后，使用光学显微镜(Reichert - Jung/ microdromat 4000E)测量涂层的厚度。在常规金相方法的基础上完成了金相制备。在该方法中，试样的横截面是用SiC磨纸和氧化铝粉机械抛光制备的。用Clemex软件测量样品的厚度。采用原子力显微镜(AFM)技术测定了涂层的粗糙度。采用低角度x射线衍射和凝视(Xpert pro MPD PANalytical)方法对热浸涂层过程中出现的相进行了检测。最后，利用扫描电镜(TESCAN, VEGA/XMU)对涂层的微观结构、厚度和出现的相进行了表征。优化热浸参数后，在α-黄铜基体上获得了高质量的Sn-Sb涂层，并通过极化测试测量了该涂层的腐蚀行为。xxx金属。板牙。Eng。Vol xx (x) 2021 p. xxx-xxx腐蚀极化试验在AutoLab PGSTAT (potentiostatgalvanostat)机器上进行，温度为25℃。在3.5% NaCl溶液中，用恒电位法求出了Tafel曲线的斜率。参比电极为Ag-AgCl，对电极为Pt。工作电极的尺寸为1×1 cm，并在面积为1cm的高质量涂层试样上进行了腐蚀试验。用循环伏安法(CV)测定了溶液的电位值。选择电位范围为0.8511 mv，扫描速率为0.5 mW/sec。最后，利用NOVA 17.8软件对提取的曲线进行解译。结果与讨论预助熔剂添加剂对镀层质量的影响本节研究了预助熔剂添加剂对镀层质量的影响。预助焊剂类型对提升涂层质量的影响如图1所示。为了准确评价预助熔剂对涂层的影响，其他热浸参数包括浸液温度、曝光时间和提取速度保持不变。 目测所得涂层的质量表明
{"title":"Comprehensive study of the effect of hot-dipping process parameters on Sn-Sb coating properties for α-brass substrate","authors":"Ali Barak, M. Tamizifar","doi":"10.30544/574","DOIUrl":"https://doi.org/10.30544/574","url":null,"abstract":"This study's main purpose is to achieve an optimal hot-dip coating condition of SnSb for an α-brass alloy. Therefore, the hot-dipping parameters, including pre-flux lubricants, immersion temperature, time, and withdrawal speed were investigated. ZnCl2 and SnCl2 were used as pre-flux bath additives. The temperature of the immersion bath was selected to be in the range of 250-300 °C. Also, the exposing time and withdrawal speed of the specimens during the hot-dipping process were in the range of 10-60 sec and 254-1524 mm/min, respectively. Visual inspection of the coating revealed that by using SnCl2 as a pre-flux additive, high-quality smooth coating is achieved. According to the AFM result, the initial roughness value of the substrate was 450 nm. The coating's roughness value with SnCl2 and SnCl2+ZnCl2 pre-fluxes were in the range of 300-500 and 700-900 nm, respectively. Therefore, ZnCl2 pre-flux is associated with a rougher surface. Corrosion test analysis revealed that both coating condition with different prefluxes leads to increasing corrosion resistance however better improvement in corrosion behavior is accomplished by smooth coating surface. The quantitative analysis of the polarization curve revealed that the corrosion rate of the smooth coating is decreased 712.5 times in comparison with the substrate. According to the SEM analysis, the predominant phases which were appeared at the interface of the coating and substrate were Cu3Sn and Cu6Sn5. SEM analysis revealed that the Cu3Sn intermetallic compound was this first phase, which was promoted near to the substrate vicinity during the hotdipping process. Keyword: α-brass alloy; hot-dipping coating; polarization curve; intermetallic; SEM. Corresponding author: Ali Barak, Alibarak77@gmail.com xxx Metall. Mater. Eng. Vol xx (x) 2021 p. xxx-xxx Introduction Brass alloys (Cu-Zn) have been regarded as commercial alloys. This alloy is one of the familiar candidates for electrical structure, pipe and valve industries due to its excellent thermal and electrical conductivity and appropriate corrosion resistance properties [1-3]. The previous studies demonstrated that the corrosion resistance of the brass alloys is severely dependent on the value of Zinc [4, 5]. As a result of dezincification, the corrosion resistance of the brass alloys was considerably dropped [69]. One practical method for protecting the corrosion behavior of engineering alloys, especially copper base alloy is coating [10]. Among different coating methods, the hotdipped method has been widely developed because of its convenience, time and costsaving issue [11]. The promoted coating has strongly protected the substrate against corrosion. The chemical composition of the coating was selected according to the working and environmental conditions [12]. Kebede et al. [13] reported a list of organic and inorganic inhibitors in order to increase the corrosion resistance of the copper base alloys. Nickel and Tin-Antimony are conventional c","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75333516","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}
Hareesha G, N. Chikkanna, S. Doddamani, Anilkumar S. Kallimani
This work aims to investigate the effect of the addition of silicon carbide particles on the microstructure and the hardness of the Al-SiC metal matrix composites. The said composite is prepared using the stir casting technique for different weight percentages of the SiC particles. The higher composition of the reinforcement causes the clustering of the particles in the matrix. Thus, research has to be carried out on the aluminum-silicon carbide composites with the reinforcement 3wt%, 6wt%, 9wt%, and 12wt% of SiC particles to obtain the optimized composition. In order to study the microstructure and the reinforcement distribution in the matrix, a scanning electron microscope is utilized. The hardness testing has been carried out using the Vickers’ indentation technique for the as-cast and age hardening conditions. From the microstructural study, it is observed that the microstructure of the said composite exhibits the uniform distribution of the reinforcement. The EDX results show the presence of the reinforcing elements in the Al-SiC composite. From the results obtained from the hardness testing, it is observed that the presence of the carbide element in the composite increases the hardness of the Al-SiC particulate composites.
{"title":"Effect of addition of SiC particles on the Microstructure and Hardness of Al-SiC composite","authors":"Hareesha G, N. Chikkanna, S. Doddamani, Anilkumar S. Kallimani","doi":"10.30544/590","DOIUrl":"https://doi.org/10.30544/590","url":null,"abstract":"This work aims to investigate the effect of the addition of silicon carbide particles on the microstructure and the hardness of the Al-SiC metal matrix composites. The said composite is prepared using the stir casting technique for different weight percentages of the SiC particles. The higher composition of the reinforcement causes the clustering of the particles in the matrix. Thus, research has to be carried out on the aluminum-silicon carbide composites with the reinforcement 3wt%, 6wt%, 9wt%, and 12wt% of SiC particles to obtain the optimized composition. In order to study the microstructure and the reinforcement distribution in the matrix, a scanning electron microscope is utilized. The hardness testing has been carried out using the Vickers’ indentation technique for the as-cast and age hardening conditions. From the microstructural study, it is observed that the microstructure of the said composite exhibits the uniform distribution of the reinforcement. The EDX results show the presence of the reinforcing elements in the Al-SiC composite. From the results obtained from the hardness testing, it is observed that the presence of the carbide element in the composite increases the hardness of the Al-SiC particulate composites.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"2016 1","pages":"49-56"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86641563","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}
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