N. Somani, Arminder Singh Walia, Nitin Kumar Gupta, Jyoti Prakash Panda, Anshuman Das, Sudhansu Ranjan Das
Electrical discharge machining (EDM) is mainly utilized for the die manufacturing and also used to machine the hard materials. Pure Copper, Copper based alloys, brass, graphite, steel are the conventional electrode materials for EDM process. While machining with the conventional electrode materials, tool wear becomes the main bottleneck which led to increased machining cost. In the present work, the composite tool tip comprises 80% Copper and 20% silicon carbide was used for the machining of hardened D2 steel. The powder metallurgy route was used to fabricate the composite tool tip. Electrode wear rate and surface roughness were assessed with respect to the different process parameters like input current, gap voltage, pulse on time, pulse off time and dielectric flushing pressure. During the analysis it was found that Input current (I p ), Pulse on time (T on ) and Pulse off time (T off ) were the significant parameters which were affecting the tool wear rate (TWR) while the I p , T on and flushing pressure affected more the surface roughness (SR). SEM micrograph reveals that increase in I p leads to increase in the wear rate of the tool. The data obtained from experiments were used to develop machine learning based surrogate models. Three machine learning (ML) models are random forest, polynomial regression and gradient boosted tree. The predictive capability of ML based surrogate models was assessed by contrasting the R 2 and mean square error (MSE) of prediction of responses. The best surrogate model was used to develop a complex objective function for use in firefly algorithm-based optimization of input machining parameters for minimization of the output responses.
电火花加工（EDM）主要用于模具制造，也可用于加工硬质材料。纯铜、铜基合金、黄铜、石墨、钢是电火花加工的传统电极材料。使用传统电极材料进行加工时，刀具磨损成为主要瓶颈，导致加工成本增加。在本研究中，由 80% 的铜和 20% 的碳化硅组成的复合刀尖被用于加工淬硬的 D2 钢。复合刀尖采用粉末冶金工艺制作。评估了电极磨损率和表面粗糙度与不同工艺参数的关系，如输入电流、间隙电压、脉冲开启时间、脉冲关闭时间和电介质冲洗压力。分析发现，输入电流（I p）、脉冲开启时间（T on）和脉冲关闭时间（T off）是影响工具磨损率（TWR）的重要参数，而 I p、T on 和冲洗压力对表面粗糙度（SR）的影响更大。SEM 显微照片显示，I p 的增加会导致刀具磨损率的增加。实验获得的数据被用于开发基于机器学习的代用模型。随机森林、多项式回归和梯度提升树是三种机器学习（ML）模型。通过对比反应预测的 R 2 和均方误差 (MSE)，评估了基于 ML 的代用模型的预测能力。最佳代用模型被用于开发一个复杂的目标函数，以用于基于萤火虫算法的输入加工参数优化，从而使输出响应最小化。
{"title":"Data driven surrogate model-based optimization of the process parameters in electric discharge machining of D2 steel using Cu-SiC composite tool for the machined surface roughness and the tool wear","authors":"N. Somani, Arminder Singh Walia, Nitin Kumar Gupta, Jyoti Prakash Panda, Anshuman Das, Sudhansu Ranjan Das","doi":"10.3989/revmetalm.242","DOIUrl":"https://doi.org/10.3989/revmetalm.242","url":null,"abstract":"Electrical discharge machining (EDM) is mainly utilized for the die manufacturing and also used to machine the hard materials. Pure Copper, Copper based alloys, brass, graphite, steel are the conventional electrode materials for EDM process. While machining with the conventional electrode materials, tool wear becomes the main bottleneck which led to increased machining cost. In the present work, the composite tool tip comprises 80% Copper and 20% silicon carbide was used for the machining of hardened D2 steel. The powder metallurgy route was used to fabricate the composite tool tip. Electrode wear rate and surface roughness were assessed with respect to the different process parameters like input current, gap voltage, pulse on time, pulse off time and dielectric flushing pressure. During the analysis it was found that Input current (I p ), Pulse on time (T on ) and Pulse off time (T off ) were the significant parameters which were affecting the tool wear rate (TWR) while the I p , T on and flushing pressure affected more the surface roughness (SR). SEM micrograph reveals that increase in I p leads to increase in the wear rate of the tool. The data obtained from experiments were used to develop machine learning based surrogate models. Three machine learning (ML) models are random forest, polynomial regression and gradient boosted tree. The predictive capability of ML based surrogate models was assessed by contrasting the R 2 and mean square error (MSE) of prediction of responses. The best surrogate model was used to develop a complex objective function for use in firefly algorithm-based optimization of input machining parameters for minimization of the output responses.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139275395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of Ni concentration on the microstructure and wear performance of 13Cr-(0.5-7.0)Ni-W-Mo-Mn-2C white cast iron subjected to homogenization heat treatment was examined. Concentration of Ni was altered in the range 0.5-7.0 wt.% to obtain a stable microstructure against for dry sliding wear resistance as long sliding distance. The effect of Ni on the microstructure was analysed by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, elemental mapping and hardness. The wear performances were tested under the loads of 40, 90 and 140 N. Differential thermal analysis of samples with dissimilar Ni values was performed. The increase of Ni concentration decreased the secondary arm spacing of dendrites, refined the dendritic structure and raised the eutectic carbide ratio. The greatest wear performance was obtained for the sample having Ni over 6 wt.%.
研究了镍浓度对经过均质热处理的 13Cr-(0.5-7.0)Ni-W-Mo-Mn-2C 白口铸铁的微观结构和磨损性能的影响。在 0.5-7.0 wt.% 的范围内改变镍的浓度，以获得稳定的微观结构，从而获得长滑动距离的干滑动耐磨性。通过 X 射线衍射、扫描电子显微镜、能量色散 X 射线光谱、元素图谱和硬度分析了镍对微观结构的影响。对不同镍值的样品进行了差热分析。镍浓度的增加降低了树枝状晶的次生臂间距，细化了树枝状晶结构，提高了共晶碳化物比率。镍含量超过 6 wt.% 的样品磨损性能最好。
{"title":"Effect of Ni on microstructure and wear behaviour of 13Cr-W-Mo-2C white cast iron","authors":"Tanju Teker, S. Osman Yılmaz","doi":"10.3989/revmetalm.243","DOIUrl":"https://doi.org/10.3989/revmetalm.243","url":null,"abstract":"The effect of Ni concentration on the microstructure and wear performance of 13Cr-(0.5-7.0)Ni-W-Mo-Mn-2C white cast iron subjected to homogenization heat treatment was examined. Concentration of Ni was altered in the range 0.5-7.0 wt.% to obtain a stable microstructure against for dry sliding wear resistance as long sliding distance. The effect of Ni on the microstructure was analysed by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, elemental mapping and hardness. The wear performances were tested under the loads of 40, 90 and 140 N. Differential thermal analysis of samples with dissimilar Ni values was performed. The increase of Ni concentration decreased the secondary arm spacing of dendrites, refined the dendritic structure and raised the eutectic carbide ratio. The greatest wear performance was obtained for the sample having Ni over 6 wt.%.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139272710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The 300 series austenitic stainless steels are widely used in industries due to their special properties. High heat in fusion welding reduces the properties of these steels and causes many problems. Therefore, stir friction spot welding, which is a type of solid state welding, is useful and widely used in high-tech industries. In this paper, a 3D dynamic explicit finite element model is developed to simulate the friction stir spot welding of 304L stainless steel plates. Using this model, the temperature distribution and the size of weld zones (thickness of weld zones) are obtained. Then, by experimental study, the results of the temperature and the size of weld zones were obtained to be a criterion for comparing and validating the numerical results. Microstructure and hardness of these zones are determined experimentally. Finally, a mathematical model based on the response surface methodology is proposed to predict the size of weld zones. Good agreement between the numerical results that are produced by the finite element simulation, the proposed model and the experimental data is observed. The results show the maximum temperature level appears in the stir zone and it reduces by moving from the weld center. Also, by increasing the rotational speed, plunging depth and dwell time of the tool, the size of both the stir zone and the heat affected zone increase to a peak value and then the size of the latter zone decreases.
{"title":"Predicting the weld zones size in FSSW of 304L stainless steel plates by mathematical model based on RSM","authors":"Amir Hossein Daei-Sorkhabi","doi":"10.3989/revmetalm.240","DOIUrl":"https://doi.org/10.3989/revmetalm.240","url":null,"abstract":"The 300 series austenitic stainless steels are widely used in industries due to their special properties. High heat in fusion welding reduces the properties of these steels and causes many problems. Therefore, stir friction spot welding, which is a type of solid state welding, is useful and widely used in high-tech industries. In this paper, a 3D dynamic explicit finite element model is developed to simulate the friction stir spot welding of 304L stainless steel plates. Using this model, the temperature distribution and the size of weld zones (thickness of weld zones) are obtained. Then, by experimental study, the results of the temperature and the size of weld zones were obtained to be a criterion for comparing and validating the numerical results. Microstructure and hardness of these zones are determined experimentally. Finally, a mathematical model based on the response surface methodology is proposed to predict the size of weld zones. Good agreement between the numerical results that are produced by the finite element simulation, the proposed model and the experimental data is observed. The results show the maximum temperature level appears in the stir zone and it reduces by moving from the weld center. Also, by increasing the rotational speed, plunging depth and dwell time of the tool, the size of both the stir zone and the heat affected zone increase to a peak value and then the size of the latter zone decreases.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135813675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Los intercambiadores de calor (IC) están formados por tubos de cobre y acero y se utilizan para calentar y enfriar el aire del ambiente. Uno de los principales problemas que se observan en los IC son las fugas en las tuberías de cobre. En este estudio, se examinaron en detalle muestras de tuberías de cobre fallidas y en buen estado de funcionamiento utilizadas durante diferentes periodos de tiempo. Los análisis microestructurales se realizaron mediante microscopía óptica (MO) y microscopía electrónica de barrido (MEB) para detectar los casos de corrosión en las superficies de las tuberías de cobre. Además, se definieron los productos de corrosión de las muestras mediante difracción de rayos X (DRX), espectroscopia de energía dispersiva (EDS) y análisis de espectroscopia infrarroja con transformada de fourier (FTIR). Se observó la formación de túneles interconectados en la sección transversal de la muestra de tubería de cobre fallida que tenían dimensiones microscópicas y productos de corrosión. En consecuencia, todos los resultados de los análisis que se obtuvieron de las muestras apuntaban a un mecanismo de corrosión conocido como corrosión por nido de hormiga. Se concluyó que la razón principal de la corrosión estaba relacionada con los aditivos de tipo etilenglicol que se utilizaban en los IC junto con el agua de red.
{"title":"Análisis de fallos de los tubos de cobre utilizados en los intercambiadores de calor de los ventiloconvectores","authors":"Fatih Sargın, Kürşat Kanbur, İlyas Türkmen","doi":"10.3989/revmetalm.239","DOIUrl":"https://doi.org/10.3989/revmetalm.239","url":null,"abstract":"Los intercambiadores de calor (IC) están formados por tubos de cobre y acero y se utilizan para calentar y enfriar el aire del ambiente. Uno de los principales problemas que se observan en los IC son las fugas en las tuberías de cobre. En este estudio, se examinaron en detalle muestras de tuberías de cobre fallidas y en buen estado de funcionamiento utilizadas durante diferentes periodos de tiempo. Los análisis microestructurales se realizaron mediante microscopía óptica (MO) y microscopía electrónica de barrido (MEB) para detectar los casos de corrosión en las superficies de las tuberías de cobre. Además, se definieron los productos de corrosión de las muestras mediante difracción de rayos X (DRX), espectroscopia de energía dispersiva (EDS) y análisis de espectroscopia infrarroja con transformada de fourier (FTIR). Se observó la formación de túneles interconectados en la sección transversal de la muestra de tubería de cobre fallida que tenían dimensiones microscópicas y productos de corrosión. En consecuencia, todos los resultados de los análisis que se obtuvieron de las muestras apuntaban a un mecanismo de corrosión conocido como corrosión por nido de hormiga. Se concluyó que la razón principal de la corrosión estaba relacionada con los aditivos de tipo etilenglicol que se utilizaban en los IC junto con el agua de red.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135813817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Turkey’s iron ores may be used to manufacture sponge iron, and the country’s coal resources, which are plentiful despite being of poor quality, can be used as a reducing agent. With such a production, Electric Arc Furnace based on scrap imports, will be an alternative raw material for steel production, and this will create high value due to the usage of domestic resources. In this study, sponge iron production was tried to be optimized by using local sources. For this purpose, the effects of time, temperature and [CFix/FeTotal] weight ratio on the Reduction Degree (%) of the important parameters effective in the production of sponge iron by using Divriği Iron Pellets and Dodurga Lignite as a reductant were studied using a Box-Wilson experimental design. The optimum parameters were determined as 82.59 min, 996.73 °C and 0.49, and the highest Reduction Degree (%) value was calculated as 96.46%. The sponge iron obtained with a 71.91% Reduction Degree contains 97.12% Fe, of which 7.12% is oxidized. It is evident that higher Fe contents may be attained with research carried out in optimum parameters.
{"title":"Optimization of sponge iron (direct reduced iron) production with Box-Wilson experimental design by using iron pellets and lignite as reductant","authors":"İbrahim Sönmez, Kemal Şahbudak","doi":"10.3989/revmetalm.241","DOIUrl":"https://doi.org/10.3989/revmetalm.241","url":null,"abstract":"Turkey’s iron ores may be used to manufacture sponge iron, and the country’s coal resources, which are plentiful despite being of poor quality, can be used as a reducing agent. With such a production, Electric Arc Furnace based on scrap imports, will be an alternative raw material for steel production, and this will create high value due to the usage of domestic resources. In this study, sponge iron production was tried to be optimized by using local sources. For this purpose, the effects of time, temperature and [CFix/FeTotal] weight ratio on the Reduction Degree (%) of the important parameters effective in the production of sponge iron by using Divriği Iron Pellets and Dodurga Lignite as a reductant were studied using a Box-Wilson experimental design. The optimum parameters were determined as 82.59 min, 996.73 °C and 0.49, and the highest Reduction Degree (%) value was calculated as 96.46%. The sponge iron obtained with a 71.91% Reduction Degree contains 97.12% Fe, of which 7.12% is oxidized. It is evident that higher Fe contents may be attained with research carried out in optimum parameters.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135870478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although the prediction of earing in the cup drawing process is considerably related to the yield surface shape, the yield surface evolution is also essential for the final ear form. The bending-unbending issue is a fundamental subject occurring on the die and punch shoulders. Since the yield stress is loading path dependent in reversal loadings, the conventional hardening models used in the monotonic loading conditions bring about inaccurate outcomes for predicting the ultimate earing profile, and a kinematic hardening model should be incorporated into the constitutive equations. This study elucidates the yield surface evolution effect involving expansion and translation simultaneously on the ear formation. A sixth-order polynomial yield function was employed to precisely characterize the yield surface shape, while a combined isotropic-kinematic hardening model was implemented to represent the evolution of the yield surface. The translation of the yield surface position was defined by the Armstrong-Frederic hardening model. Punch force-stroke responses and the ear form profiles were predicted by the implemented plasticity model in Marc using the Hypela2 user subroutine and compared with the experimental results. The combined hardening assumption yielded an increase in the mean cup height when compared to the isotropic hardening assumption. Moreover, The HomPol6 coupled with the combined hardening showed a better agreement with the experimental results.
{"title":"Effect of the yield surface evolution on the earing defect prediction","authors":"T. Akşen, Mehmet Firat","doi":"10.3989/revmetalm.235","DOIUrl":"https://doi.org/10.3989/revmetalm.235","url":null,"abstract":"Although the prediction of earing in the cup drawing process is considerably related to the yield surface shape, the yield surface evolution is also essential for the final ear form. The bending-unbending issue is a fundamental subject occurring on the die and punch shoulders. Since the yield stress is loading path dependent in reversal loadings, the conventional hardening models used in the monotonic loading conditions bring about inaccurate outcomes for predicting the ultimate earing profile, and a kinematic hardening model should be incorporated into the constitutive equations. This study elucidates the yield surface evolution effect involving expansion and translation simultaneously on the ear formation. A sixth-order polynomial yield function was employed to precisely characterize the yield surface shape, while a combined isotropic-kinematic hardening model was implemented to represent the evolution of the yield surface. The translation of the yield surface position was defined by the Armstrong-Frederic hardening model. Punch force-stroke responses and the ear form profiles were predicted by the implemented plasticity model in Marc using the Hypela2 user subroutine and compared with the experimental results. The combined hardening assumption yielded an increase in the mean cup height when compared to the isotropic hardening assumption. Moreover, The HomPol6 coupled with the combined hardening showed a better agreement with the experimental results.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42961260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, integrated computational materials engineering, which is one of the new generation approaches in materials science, was used in the production of aluminum alloy wheels by low pressure die casting method. In casting alloys, the efficiency of grain refinement provided by master alloys added to the melt decreases with increasing silicon content of the alloy. In this context, as-cast properties of silicon reduced (Si: 5.0 wt.%) alloys with different Mg ratios (Mg: 3.0, 5.0, 7.0 wt.%) are discussed using integrated computational materials engineering approaches. It has been evaluated whether the examined alloys can be an alternative to the AlSi7Mg0.3 alloy, which is currently used traditionally in the production of aluminum-based wheels, with their microstructural and mechanical properties. The study consists of three stages which are computer-aided production, pilot production, testing and characterization studies. In computer-aided production, original sub-eutectic compositions were determined in types and amounts of alloying elements, alloy designs were realized and a database was created with a computational materials engineering software. Then, low pressure die casting analysis were performed in a virtual environment by transferring these data directly to the casting simulation software. Thus, the microstructural and mechanical properties of the wheel were obtained computationally on the basis of the varying alloy composition. In the second stage, the virtually designed alloy compositions were prepared and sample wheels were manufactured by the low pressure die casting method on an industrial scale. In the testing and characterization phase, spectral analyses, macro and microstructural examinations, hardness measurements and tensile tests were carried out. As a result of this study, it was determined that the studied alloys could be used in the production of wheels by the low pressure die casting method considering the metallurgical properties expected from the wheel. In addition, it is thought that the mathematical design of the material with integrated computational materials engineering approaches before casting simulations will play an active role in the competitiveness and sustainability of the aluminum industry in technological conditions.
{"title":"Investigation of metallurgical properties of Al-Si-Mg casting alloys with integrated computational materials engineering for wheel production","authors":"T. Yağcı, Ü. Cöcen, O. Çulha, E. Armakan","doi":"10.3989/revmetalm.233","DOIUrl":"https://doi.org/10.3989/revmetalm.233","url":null,"abstract":"In this study, integrated computational materials engineering, which is one of the new generation approaches in materials science, was used in the production of aluminum alloy wheels by low pressure die casting method. In casting alloys, the efficiency of grain refinement provided by master alloys added to the melt decreases with increasing silicon content of the alloy. In this context, as-cast properties of silicon reduced (Si: 5.0 wt.%) alloys with different Mg ratios (Mg: 3.0, 5.0, 7.0 wt.%) are discussed using integrated computational materials engineering approaches. It has been evaluated whether the examined alloys can be an alternative to the AlSi7Mg0.3 alloy, which is currently used traditionally in the production of aluminum-based wheels, with their microstructural and mechanical properties. The study consists of three stages which are computer-aided production, pilot production, testing and characterization studies. In computer-aided production, original sub-eutectic compositions were determined in types and amounts of alloying elements, alloy designs were realized and a database was created with a computational materials engineering software. Then, low pressure die casting analysis were performed in a virtual environment by transferring these data directly to the casting simulation software. Thus, the microstructural and mechanical properties of the wheel were obtained computationally on the basis of the varying alloy composition. In the second stage, the virtually designed alloy compositions were prepared and sample wheels were manufactured by the low pressure die casting method on an industrial scale. In the testing and characterization phase, spectral analyses, macro and microstructural examinations, hardness measurements and tensile tests were carried out. As a result of this study, it was determined that the studied alloys could be used in the production of wheels by the low pressure die casting method considering the metallurgical properties expected from the wheel. In addition, it is thought that the mathematical design of the material with integrated computational materials engineering approaches before casting simulations will play an active role in the competitiveness and sustainability of the aluminum industry in technological conditions.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41426855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Resistance spot welding (RSW) is widely used as a main joining technique in industry and the electrode caps are frequently replaced because of the degradation during service. In this study, the G type copper RSW electrode caps were coated with Fe and Ni based Fe3Al, FeAl, Ni3Al, NiAl alloys by Electro-Spark Deposition (ESD), providing resistance to hot deformation, oxidation and Zn evaporation from sheet metal. The ESD coated electrode caps were tested in-situ on a hot dip galvanized steel in order to assess the performance of RSW electrode caps. For this purpose, three different coating voltages were selected for each coated electrode, and 12 different cap coatings were produced in total. Fifty resistance spot welds were consecutively manufactured with the same parameters for each type of coating electrodes. Hardness measurements, macrostructural examination, Ultrasonic Testing (UT) and chisel tests were performed on welded samples produced. In addition, effects of different coatings on RSW electrode caps were investigated on microstructural development, hardness variations and deformation capacity of resistance spot welds. Results showed that chisel tests and cross section thickness values of the welded sample made with the caps that were ESD coated with the Ni3Al electrode produced better results than the other caps. The cross-sectional thickness of nuggets was lower in all 158 V coated caps. The performance of aluminide coatings on RSW electrode caps can be listed from the best to the worst in the order of Ni3Al, NiAl, Fe3Al, and FeAl.
{"title":"Performance of resistance spot weld caps coated with Ni and Fe aluminide alloys by electro spark deposition on hot dip galvanized steel","authors":"İbrahim F. Açış, Ş. Talaş","doi":"10.3989/revmetalm.237","DOIUrl":"https://doi.org/10.3989/revmetalm.237","url":null,"abstract":"Resistance spot welding (RSW) is widely used as a main joining technique in industry and the electrode caps are frequently replaced because of the degradation during service. In this study, the G type copper RSW electrode caps were coated with Fe and Ni based Fe3Al, FeAl, Ni3Al, NiAl alloys by Electro-Spark Deposition (ESD), providing resistance to hot deformation, oxidation and Zn evaporation from sheet metal. The ESD coated electrode caps were tested in-situ on a hot dip galvanized steel in order to assess the performance of RSW electrode caps. For this purpose, three different coating voltages were selected for each coated electrode, and 12 different cap coatings were produced in total. Fifty resistance spot welds were consecutively manufactured with the same parameters for each type of coating electrodes. Hardness measurements, macrostructural examination, Ultrasonic Testing (UT) and chisel tests were performed on welded samples produced. In addition, effects of different coatings on RSW electrode caps were investigated on microstructural development, hardness variations and deformation capacity of resistance spot welds. Results showed that chisel tests and cross section thickness values of the welded sample made with the caps that were ESD coated with the Ni3Al electrode produced better results than the other caps. The cross-sectional thickness of nuggets was lower in all 158 V coated caps. The performance of aluminide coatings on RSW electrode caps can be listed from the best to the worst in the order of Ni3Al, NiAl, Fe3Al, and FeAl.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49669857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana R. Salazar-Román, Jorge López-Cuevas, Carlos R. Arganis-Juárez, José C. Méndez-García, Juan C. Rendón-Angeles
Oxide dispersion strengthened (ODS) ferritic alloys are structural materials used in nuclear fusion reactors, which exhibit enhanced mechanical properties, as well as corrosion and irradiation resistance. In the present work, ODS ferritic alloys with composition Fe-14Cr-1.5W-0.4Ti-(0, 0.4, 0.8) Y2O3 (in wt.%) were prepared employing high energy milling (HEM) followed by Spark Plasma Sintering (SPS). The particle size distribution (PSD) of the milled powders was characterized by laser diffraction. These powders and the sintered materials produced were characterized using X-ray diffraction (XRD), and scanning electron microscopy (SEM). The sintered materials were also characterized by dilatometry, diametral compression, Vickers microhardness, and corrosion rate tests. The largest Young’s modulus, microhardness, and dimensional shrinkage/expansion were obtained for the 0.8 wt.% Y2O3 alloy. However, this alloy was the least ductile. Furthermore, the 0.8 wt.% Y2O3 alloy was the one with the least dimensional change. According to the potentiodynamic polarization studies, it was found that the protective layer of Cr2O3 formed on the surface of the three alloys studied was less effective for the yttria-free alloy, since in this case the rupture of such protective layer occurred earlier than for the case of the yttria-containing alloys. Based on these results, it is suggested that the 0.8 wt.% Y2O3 alloy having fine microstructure could constitute a potential alternative as a structural material for Gen IV-type reactors.
{"title":"Effect of yttria addition on the microstructure and mechanical behavior of ODS ferritic alloys processed by High Energy Milling and Spark Plasma Sintering","authors":"Ana R. Salazar-Román, Jorge López-Cuevas, Carlos R. Arganis-Juárez, José C. Méndez-García, Juan C. Rendón-Angeles","doi":"10.3989/revmetalm.236","DOIUrl":"https://doi.org/10.3989/revmetalm.236","url":null,"abstract":"Oxide dispersion strengthened (ODS) ferritic alloys are structural materials used in nuclear fusion reactors, which exhibit enhanced mechanical properties, as well as corrosion and irradiation resistance. In the present work, ODS ferritic alloys with composition Fe-14Cr-1.5W-0.4Ti-(0, 0.4, 0.8) Y2O3 (in wt.%) were prepared employing high energy milling (HEM) followed by Spark Plasma Sintering (SPS). The particle size distribution (PSD) of the milled powders was characterized by laser diffraction. These powders and the sintered materials produced were characterized using X-ray diffraction (XRD), and scanning electron microscopy (SEM). The sintered materials were also characterized by dilatometry, diametral compression, Vickers microhardness, and corrosion rate tests. The largest Young’s modulus, microhardness, and dimensional shrinkage/expansion were obtained for the 0.8 wt.% Y2O3 alloy. However, this alloy was the least ductile. Furthermore, the 0.8 wt.% Y2O3 alloy was the one with the least dimensional change. According to the potentiodynamic polarization studies, it was found that the protective layer of Cr2O3 formed on the surface of the three alloys studied was less effective for the yttria-free alloy, since in this case the rupture of such protective layer occurred earlier than for the case of the yttria-containing alloys. Based on these results, it is suggested that the 0.8 wt.% Y2O3 alloy having fine microstructure could constitute a potential alternative as a structural material for Gen IV-type reactors.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136121542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thomas Gomes dos Santos, A. Rosiak, D. R. Alba, Diego Pacheco Wermuth, Matheus Henrique Riffel, Rafael Pandolfo da Rocha, Lirio Schaeffe
Drawing is a manufacturing process that consists of indirect deformation by pulling the material through a tool with a conical geometry. The process is usually performed at room temperature (cold forming), so the selection of effective lubricants is critical. If lubrication is inadequate, there is a high risk that both, tool and the manufactured wire, will fail. In this study, annealed AISI 1020 steel rods were drawn and the effectiveness of three different industrial lubricants was tested. During the process, the drawing force values were recorded and used to determine the friction coefficient that developed under each lubrication condition. Numerical simulations were performed to further understand the process. Based on the experimental and numerical results, qualitative and quantitative analysis were performed for each condition. Among the different lubricants used in this study, zinc stearate showed the lowest value for drawing force, 18.8 kN, followed by Lub A and B with values of 20 kN and 20.6 kN, respectively. The numerical models showed excellent approximation to the force values determined in the tests. The values for the coefficient of friction obtained by both the numerical analysis and the empirical model indicate that zinc stearate has the highest lubricating effect among the lubricants focused on this study.
{"title":"Experimental-numerical analysis to determine the efficiency of industrial lubricants in wire drawing process","authors":"Thomas Gomes dos Santos, A. Rosiak, D. R. Alba, Diego Pacheco Wermuth, Matheus Henrique Riffel, Rafael Pandolfo da Rocha, Lirio Schaeffe","doi":"10.3989/revmetalm.234","DOIUrl":"https://doi.org/10.3989/revmetalm.234","url":null,"abstract":"Drawing is a manufacturing process that consists of indirect deformation by pulling the material through a tool with a conical geometry. The process is usually performed at room temperature (cold forming), so the selection of effective lubricants is critical. If lubrication is inadequate, there is a high risk that both, tool and the manufactured wire, will fail. In this study, annealed AISI 1020 steel rods were drawn and the effectiveness of three different industrial lubricants was tested. During the process, the drawing force values were recorded and used to determine the friction coefficient that developed under each lubrication condition. Numerical simulations were performed to further understand the process. Based on the experimental and numerical results, qualitative and quantitative analysis were performed for each condition. Among the different lubricants used in this study, zinc stearate showed the lowest value for drawing force, 18.8 kN, followed by Lub A and B with values of 20 kN and 20.6 kN, respectively. The numerical models showed excellent approximation to the force values determined in the tests. The values for the coefficient of friction obtained by both the numerical analysis and the empirical model indicate that zinc stearate has the highest lubricating effect among the lubricants focused on this study.","PeriodicalId":21206,"journal":{"name":"Revista De Metalurgia","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46009870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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