Mechanical shields can effectively alleviate the problems of low pesticide utilization and severe environmental pollution. This manuscript uses a computational fluid dynamics (CFD) method to investigate the anti-drift mechanism of mechanical shields, study the airflow forms around them, and establish an accurate simulation model. The aerodynamic characteristics of six shields were studied, and their anti-drift effect was compared. Then, the size and working parameters were optimized using the response surface methodology (RSM). Mechanical shields can significantly improve the fog droplet deposition rate (DR) compared with the conventional spray method (no shield), among which the umbrella-type shield has the best effect; optimizing the size and selecting suitable working parameters can increase the DR to 77.31 %. The field trial showed that the DR of the conventional spray method was reduced by 31.9 % at 5 m/s compared with 3 m/s, while the DR of the shield spray method was reduced by only 3.6 % at 5 m/s compared with 3 m/s, which proved the excellent performance of the mechanical shields. The field trial results were consistent with the CFD simulation, and the relative deviation of the DR between the two was within 4 %, so the accuracy and reliability of the CFD simulation model were proved.
{"title":"Design and Optimization of an Umbrella-Type Shield Based on 3D CFD Simulation Technology","authors":"Longfei Li, Xin He, Taowei Jiao, Yumeng Xiao, Xipan Wei, Wei Li","doi":"10.5545/sv-jme.2023.644","DOIUrl":"https://doi.org/10.5545/sv-jme.2023.644","url":null,"abstract":"Mechanical shields can effectively alleviate the problems of low pesticide utilization and severe environmental pollution. This manuscript uses a computational fluid dynamics (CFD) method to investigate the anti-drift mechanism of mechanical shields, study the airflow forms around them, and establish an accurate simulation model. The aerodynamic characteristics of six shields were studied, and their anti-drift effect was compared. Then, the size and working parameters were optimized using the response surface methodology (RSM). Mechanical shields can significantly improve the fog droplet deposition rate (DR) compared with the conventional spray method (no shield), among which the umbrella-type shield has the best effect; optimizing the size and selecting suitable working parameters can increase the DR to 77.31 %. The field trial showed that the DR of the conventional spray method was reduced by 31.9 % at 5 m/s compared with 3 m/s, while the DR of the shield spray method was reduced by only 3.6 % at 5 m/s compared with 3 m/s, which proved the excellent performance of the mechanical shields. The field trial results were consistent with the CFD simulation, and the relative deviation of the DR between the two was within 4 %, so the accuracy and reliability of the CFD simulation model were proved.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134914950","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 deals with fuzzy logic based modeling and parametric analysis in powder mixed electrical discharge machining of titanium alloys. The central composition plan was used to design the experiments considering four parameters, namely discharge current, pulse duration, duty cycle as well as graphite powder concentration. All experiments were performed with different parameter combinations and the performance, i.e., surface roughness, was evaluated. The adaptive neuro-fuzzy inference system was used to understand and define the input-output relationship. The experimental results and the model results were compared and it was found that the results accurately predicted the reactions in the erosion of titanium alloys. In addition, the model was verified using data that had not participated in the training of the model, with an error of about 10%. In addition, a fuzzy plot was used to analyze the influence of input parameters on surface roughness. It was found that the discharge current was the most important influencing parameter. Additional experiments proved the positive effect of graphite powder, which reduced the surface roughness by 27 %.
{"title":"Fuzzy Logic Approach to Predict Surface Roughness in Powder Mixed Electric Discharge Machining of Titanium Alloy","authors":"Dragan Rodić, Marin Gostimirović, Milenko Sekulić, Borislav Savković, Andjelko Aleksić","doi":"10.5545/sv-jme.2023.561","DOIUrl":"https://doi.org/10.5545/sv-jme.2023.561","url":null,"abstract":"This study deals with fuzzy logic based modeling and parametric analysis in powder mixed electrical discharge machining of titanium alloys. The central composition plan was used to design the experiments considering four parameters, namely discharge current, pulse duration, duty cycle as well as graphite powder concentration. All experiments were performed with different parameter combinations and the performance, i.e., surface roughness, was evaluated. The adaptive neuro-fuzzy inference system was used to understand and define the input-output relationship. The experimental results and the model results were compared and it was found that the results accurately predicted the reactions in the erosion of titanium alloys. In addition, the model was verified using data that had not participated in the training of the model, with an error of about 10%. In addition, a fuzzy plot was used to analyze the influence of input parameters on surface roughness. It was found that the discharge current was the most important influencing parameter. Additional experiments proved the positive effect of graphite powder, which reduced the surface roughness by 27 %.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134915147","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}
Copper metal matrix composites (CMC) are broadly employed in various applications in the fields of space, aviation, automobile and electronics industries. The welding of CMC in using conventional methods is very difficult and expensive due to its crystallographic nature. Friction stir welding (FSW) is a more prominent and reliable technique for welding than conventional methods. Therefore, this work is based on work with CMC material, which is prepared with a stir-casting technique. Pure copper (Cu) is reinforced with tungsten (W) and boron carbide (B4C) particles in different combinations and welded using the FSW process to study the mechanical and micro-structural properties. Multi-objective decision-making methods, such as the technique for order preference by similarity to ideal solution (TOPSIS) and grey relational analysis (GRA) are used to find optimal parameter combination. The experiments are planned according to the L 18 orthogonal array (OA) using the most influential parameters, such as reinforcement the percentage of B4C, tool rotational speed, welding speed, and axial force. The performance of outcomes is measured based on the responses such as tensile strength, hardness, and impact strength of the weld joint. Based on the results 15 % of B4C reinforcement, 900 RPM rotational speed, 15 mm/min welding speed and 6 kN axial forces are optimal for better mechanical strength in the welding with TOPSIS and GRA techniques. Additionally, scanning electron microscopic image (SEM) analyses were carried out for better understanding of weldments’ microstructure changes.
铜金属基复合材料在航天、航空、汽车、电子等工业领域有着广泛的应用。由于CMC的结晶性质，用传统方法焊接CMC非常困难和昂贵。搅拌摩擦焊(FSW)是一种比传统焊接方法更为突出和可靠的焊接技术。因此，本工作是以搅拌铸造技术制备的CMC材料为基础的。用不同组合的碳化钨(W)和碳化硼(B4C)颗粒增强纯铜(Cu)，并采用FSW工艺焊接，研究其力学性能和微观组织性能。采用多目标决策方法，如TOPSIS (order preference by similarity to ideal solution)和GRA(灰色关联分析)来寻找最优的参数组合。根据l18正交阵列(OA)，选取对补强率影响最大的参数，如补强率、B4C的掺量、刀具转速、焊接速度和轴向力，对试验进行规划。结果的性能是根据焊接接头的抗拉强度、硬度和冲击强度等响应来测量的。结果表明，在TOPSIS和GRA焊接工艺中，15%的B4C增强剂、900 RPM的转速、15 mm/min的焊接速度和6 kN的轴向力可获得较好的机械强度。此外，为了更好地了解焊接件的微观结构变化，还进行了扫描电镜(SEM)分析。
{"title":"Mechanical and Microstructural Properties of B4C/W Reinforced Copper Matrix Composite Using a Friction Stir-Welding Process","authors":"Jamuna Elangandhi, Suresh Periyagounder, Mahalingam Selavaraj, Duraisivam Saminatharaja","doi":"10.5545/sv-jme.2023.518","DOIUrl":"https://doi.org/10.5545/sv-jme.2023.518","url":null,"abstract":"Copper metal matrix composites (CMC) are broadly employed in various applications in the fields of space, aviation, automobile and electronics industries. The welding of CMC in using conventional methods is very difficult and expensive due to its crystallographic nature. Friction stir welding (FSW) is a more prominent and reliable technique for welding than conventional methods. Therefore, this work is based on work with CMC material, which is prepared with a stir-casting technique. Pure copper (Cu) is reinforced with tungsten (W) and boron carbide (B4C) particles in different combinations and welded using the FSW process to study the mechanical and micro-structural properties. Multi-objective decision-making methods, such as the technique for order preference by similarity to ideal solution (TOPSIS) and grey relational analysis (GRA) are used to find optimal parameter combination. The experiments are planned according to the L 18 orthogonal array (OA) using the most influential parameters, such as reinforcement the percentage of B4C, tool rotational speed, welding speed, and axial force. The performance of outcomes is measured based on the responses such as tensile strength, hardness, and impact strength of the weld joint. Based on the results 15 % of B4C reinforcement, 900 RPM rotational speed, 15 mm/min welding speed and 6 kN axial forces are optimal for better mechanical strength in the welding with TOPSIS and GRA techniques. Additionally, scanning electron microscopic image (SEM) analyses were carried out for better understanding of weldments’ microstructure changes.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134915146","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}
Andrzej Perec, Elzbieta Kawecka, Aleksandra Radomska-Zalas, Frank Pude
The paper shows performance optimization effects of steel machining by abrasive water jet (AWJ). An innovative combinative distance-based assessment method (CODAS) is implemented for the optimization of cutting parameters like pump pressure, feed rate, and abrasive flow rate over cutting depth, and cut kerf surface roughness. The CODAS algorithm is among those based on measuring the distance between a scenario (in this case processing parameters in terms of performance and quality indicators) - and a certain benchmark. A benchmark is a specific hypothetical set of processing parameters devised or determined from available data. To determine the best set of process control parameters, a CODAS approach was performed with some weighting determinations. To set the initial parameters of the weights, it was proposed to calculate based on entropy weight method (EWM), that measures output value dispersion in cutting process. This technique simplifies multiple compound responses by preserving a single response.
{"title":"Optimization of Abrasive Waterjet Cutting by Using the CODAS Method with Regard to Interdependent Processing Parameters","authors":"Andrzej Perec, Elzbieta Kawecka, Aleksandra Radomska-Zalas, Frank Pude","doi":"10.5545/sv-jme.2023.647","DOIUrl":"https://doi.org/10.5545/sv-jme.2023.647","url":null,"abstract":"The paper shows performance optimization effects of steel machining by abrasive water jet (AWJ). An innovative combinative distance-based assessment method (CODAS) is implemented for the optimization of cutting parameters like pump pressure, feed rate, and abrasive flow rate over cutting depth, and cut kerf surface roughness. The CODAS algorithm is among those based on measuring the distance between a scenario (in this case processing parameters in terms of performance and quality indicators) - and a certain benchmark. A benchmark is a specific hypothetical set of processing parameters devised or determined from available data. To determine the best set of process control parameters, a CODAS approach was performed with some weighting determinations. To set the initial parameters of the weights, it was proposed to calculate based on entropy weight method (EWM), that measures output value dispersion in cutting process. This technique simplifies multiple compound responses by preserving a single response.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"215 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134914951","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 coefficient of performance (COP) for a gas refrigeration cycle was estimated using Matlab/Simulink and fuzzy logic. A Matlab/Simulink model of the gas refrigeration cycle was developed, and the output was compared to theoretical data. Additionally, fuzzy logic was used to estimate the COP for arbitrary low- and high-pressure levels. Simulation results were used to develop a multi-input-multi-output (MIMO) fuzzy Takagi-Sugeno-Kang (TSK)-based model. Both the Matlab/Simulink and the MIMO fuzzy model were found to be very well correlated with theoretical results, with an error of less than 2 %. These results demonstrate the effectiveness of using fuzzy logic to analyse gas refrigeration cycles and suggest that this approach can be extended to analyse other thermodynamic cycles.
{"title":"Fuzzy and Matlab/Simulink Modelling of the Air Compression Refrigeration Cycle","authors":"Amjad Alsakarneh, Lina Momani, Taha Tabaza","doi":"10.5545/sv-jme.2023.597","DOIUrl":"https://doi.org/10.5545/sv-jme.2023.597","url":null,"abstract":"The coefficient of performance (COP) for a gas refrigeration cycle was estimated using Matlab/Simulink and fuzzy logic. A Matlab/Simulink model of the gas refrigeration cycle was developed, and the output was compared to theoretical data. Additionally, fuzzy logic was used to estimate the COP for arbitrary low- and high-pressure levels. Simulation results were used to develop a multi-input-multi-output (MIMO) fuzzy Takagi-Sugeno-Kang (TSK)-based model. Both the Matlab/Simulink and the MIMO fuzzy model were found to be very well correlated with theoretical results, with an error of less than 2 %. These results demonstrate the effectiveness of using fuzzy logic to analyse gas refrigeration cycles and suggest that this approach can be extended to analyse other thermodynamic cycles.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134915145","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}
To determine the force and energy parameters of cold roll-beating of external splines, the characteristics of the deformation zone in cold roll-beating are analysed. The geometric dimensions and position of the deformation zone change with the movement of the roller, the contact arc, and the reduction are very small, and there is an incomplete deformation zone in the initial stage of cold roll-beating. A discrete analytical method for calculating the unit pressure and deformation force is proposed, and the cold roll-beating process is discretized into an infinite number of cold-rolling processes with complex sections. The discrete analytical model of unit pressure and deformation force is established, and the unit pressure value and its distribution characteristics are determined. To verify the discrete analytical model, a finite element model of cold roll-beating is established, and the forming force is calculated. A horizontal milling machine is modified to carry out the cold roll-beating experiment, and the forming force is measured. The predicted results of the discrete analytical model are compared with the simulation and experiment results. The results show that the maximum error of radial force compared with the simulation and experiment results is about 7 % and 4 % respectively, and the variation curve of radial force is basically consistent, but the time of a cold roll-beating process is slightly shorter. The discrete analytical model correctly predicts the magnitude and change process of cold roll-beating forming force.
{"title":"Research on an Analytical Method for the Forming Force of External Spline Cold Roll-Beating","authors":"Qun Ma, Xiangwei Zhang","doi":"10.5545/sv-jme.2023.616","DOIUrl":"https://doi.org/10.5545/sv-jme.2023.616","url":null,"abstract":"To determine the force and energy parameters of cold roll-beating of external splines, the characteristics of the deformation zone in cold roll-beating are analysed. The geometric dimensions and position of the deformation zone change with the movement of the roller, the contact arc, and the reduction are very small, and there is an incomplete deformation zone in the initial stage of cold roll-beating. A discrete analytical method for calculating the unit pressure and deformation force is proposed, and the cold roll-beating process is discretized into an infinite number of cold-rolling processes with complex sections. The discrete analytical model of unit pressure and deformation force is established, and the unit pressure value and its distribution characteristics are determined. To verify the discrete analytical model, a finite element model of cold roll-beating is established, and the forming force is calculated. A horizontal milling machine is modified to carry out the cold roll-beating experiment, and the forming force is measured. The predicted results of the discrete analytical model are compared with the simulation and experiment results. The results show that the maximum error of radial force compared with the simulation and experiment results is about 7 % and 4 % respectively, and the variation curve of radial force is basically consistent, but the time of a cold roll-beating process is slightly shorter. The discrete analytical model correctly predicts the magnitude and change process of cold roll-beating forming force.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134915144","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}
Ava A.K. Mohammed, Gailan Ismail Hassan, Younis Khalid Khdir
Fibre-reinforced polymer composite has many uses in structural components that required high strength, stiffness, and damping capacity. Cross and quasi-laminated epoxy composites with and without nano Al2O3 were used in this investigation to determine flexural modulus, natural frequency, damping ratio, and mode shapes by using analytical, experimental, and numerical (ANSYS) methods. It was demonstrated that adding 2 % nano Al2O3 improved the flexural modulus and the damping ratio while decreased the natural frequency. Cross number 2 and quasi number 2 had the highest natural frequency for cross and quasi laminate groups which are equal to 23.5 Hz and 20.25 Hz experimentally, respectively. On the other hand, the higher damping ratio was achieved for cross number 1 with nano Al2O3 and quasi number 2 with nano Al2O3 for both cross and quasi laminates, which are equal to 0.707 % and 0.693 %, respectively. The flexural modulus and damping ratio are inversely related to each other. However, the novelty in this article is that by adding two glass plies at the outer surface of quasi group laminate the flexural modulus, natural frequency, and damping ratio are increased simultaneously, as in the configurations quasi number 2 and quasi number 2 with nano Al2O3 in comparison with quasi number 1 and quasi number 1 with nano Al2O3.
{"title":"The Dynamic Behaviour of Symmetrical Laminated Nano-composite Containing Equal Numbers of Glass and Carbon Fibre Layers","authors":"Ava A.K. Mohammed, Gailan Ismail Hassan, Younis Khalid Khdir","doi":"10.5545/sv-jme.2022.403","DOIUrl":"https://doi.org/10.5545/sv-jme.2022.403","url":null,"abstract":"Fibre-reinforced polymer composite has many uses in structural components that required high strength, stiffness, and damping capacity. Cross and quasi-laminated epoxy composites with and without nano Al2O3 were used in this investigation to determine flexural modulus, natural frequency, damping ratio, and mode shapes by using analytical, experimental, and numerical (ANSYS) methods. It was demonstrated that adding 2 % nano Al2O3 improved the flexural modulus and the damping ratio while decreased the natural frequency. Cross number 2 and quasi number 2 had the highest natural frequency for cross and quasi laminate groups which are equal to 23.5 Hz and 20.25 Hz experimentally, respectively. On the other hand, the higher damping ratio was achieved for cross number 1 with nano Al2O3 and quasi number 2 with nano Al2O3 for both cross and quasi laminates, which are equal to 0.707 % and 0.693 %, respectively. The flexural modulus and damping ratio are inversely related to each other. However, the novelty in this article is that by adding two glass plies at the outer surface of quasi group laminate the flexural modulus, natural frequency, and damping ratio are increased simultaneously, as in the configurations quasi number 2 and quasi number 2 with nano Al2O3 in comparison with quasi number 1 and quasi number 1 with nano Al2O3.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135642816","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}
Understanding the behaviour of propeller-driven aircraft has been the primary goal of aviation since the brothers Orville and Wilbur Wright. Traction characteristics, which have over time become dominant in the field of aviation in addition to thrust, both examined and analysed, nevertheless represent a sort of oxymoron in modern aviation. In this sense, the authors of the paper present the possibilities of static performance characteristics and vibrations of aircraft propellers through the analysis of low-powered aircraft. The use of low-powered aircraft as “expendable” material is the reality we live in, but ensuring the safety of their use is the primary goal of the researchers who deal with this issue. Accordingly, the authors of this paper present indications of the methodology of testing the blades of low-power aircraft in the atmosphere with an observation that the same indications can be used with aircraft of higher power, as well as with the aircraft on celestial bodies that have not been tested or available. A test bench for the quantification of thrust, torque, and vibration of small unmanned aerial vehicles’ (UAV) vehicle propellers is presented. The obtained results realistically describe the complex behaviour of propellers in operation.
{"title":"A Case Study of a Methodological Approach to the Verification of UAV Propeller Performance","authors":"Goran Vorotović, Jela Burazer, Aleksandar Bengin, Časlav Mitrović, Miloš Januzović, Nebojša Petrović, Djordje Novković","doi":"10.5545/sv-jme.2022.432","DOIUrl":"https://doi.org/10.5545/sv-jme.2022.432","url":null,"abstract":"Understanding the behaviour of propeller-driven aircraft has been the primary goal of aviation since the brothers Orville and Wilbur Wright. Traction characteristics, which have over time become dominant in the field of aviation in addition to thrust, both examined and analysed, nevertheless represent a sort of oxymoron in modern aviation. In this sense, the authors of the paper present the possibilities of static performance characteristics and vibrations of aircraft propellers through the analysis of low-powered aircraft. The use of low-powered aircraft as “expendable” material is the reality we live in, but ensuring the safety of their use is the primary goal of the researchers who deal with this issue. Accordingly, the authors of this paper present indications of the methodology of testing the blades of low-power aircraft in the atmosphere with an observation that the same indications can be used with aircraft of higher power, as well as with the aircraft on celestial bodies that have not been tested or available. A test bench for the quantification of thrust, torque, and vibration of small unmanned aerial vehicles’ (UAV) vehicle propellers is presented. The obtained results realistically describe the complex behaviour of propellers in operation.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135693134","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}
Haiter Lenin Allasi, Mary Vasanthi Soosaimariyan, Vettivel Singaravel Chidambaranathan
Cu matrix composites benefit from the high electrical and thermal conductivities of Cu and the mechanical wear/erosion resistance of hard reinforcement. In this study, an attempt has been made to determine the effect of the addition of reinforcement B4C in Cu-Ni-Sn. The B4C is reinforced to form a hybrid Cu matrix composite with powder metallurgy technique. The hybrid composites are obtained by milling, blending, and compacting the powders to obtain a fine grain-sized particle without aggregation. The grain size and particle nature were characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques, respectively. The microstructure, density, hardness, and wear rate of the composites were studied. The pin-on-disc method is equipped to study the wear behaviour and coefficient of friction. The sintered density of the prepared Cu-15%Ni is 98.25 %, Cu-8%Sn is 98.20 %, Cu-15%Ni-8%Sn is 98.10 % and Cu-15%Ni-8%Sn-2%B4C is 95.26 % and lower specific wear rate has been recorded for Cu-15Ni-8Sn-2B4C 121×10-6 mm3/(Nm) and the addition of reinforcement B4C in Cu-Ni-Sn displays remarkable changes in wear rate and friction coefficient.
铜基复合材料得益于铜的高导电性和热导率以及硬增强材料的耐机械磨损/侵蚀性。在本研究中，试图确定在Cu-Ni-Sn中添加增强剂B4C的效果。采用粉末冶金技术对B4C进行强化，形成杂化铜基复合材料。杂化复合材料是通过磨粉、共混和压实得到无团聚的细粒度颗粒而得到的。采用扫描电子显微镜(SEM)和x射线衍射仪(XRD)对其粒度和颗粒性质进行了表征。研究了复合材料的显微组织、密度、硬度和磨损率。采用销盘法研究摩擦磨损特性和摩擦系数。制备的Cu-15%Ni的烧结密度为98.25%，Cu-8%Sn为98.20%，Cu-15%Ni-8% sn为98.10%，Cu-15%Ni-8% sn -2%B4C为95.26%，Cu-15Ni-8Sn-2B4C的比磨损率较低121×10-6 mm3/(Nm)， Cu-Ni-Sn中加入增强剂B4C后，磨损率和摩擦系数发生了显著变化。
{"title":"Wear Behaviour of a Cu-Ni-Sn Hybrid Composite Reinforced with B4C prepared by Powder Metallurgy Technique","authors":"Haiter Lenin Allasi, Mary Vasanthi Soosaimariyan, Vettivel Singaravel Chidambaranathan","doi":"10.5545/sv-jme.2022.423","DOIUrl":"https://doi.org/10.5545/sv-jme.2022.423","url":null,"abstract":"Cu matrix composites benefit from the high electrical and thermal conductivities of Cu and the mechanical wear/erosion resistance of hard reinforcement. In this study, an attempt has been made to determine the effect of the addition of reinforcement B4C in Cu-Ni-Sn. The B4C is reinforced to form a hybrid Cu matrix composite with powder metallurgy technique. The hybrid composites are obtained by milling, blending, and compacting the powders to obtain a fine grain-sized particle without aggregation. The grain size and particle nature were characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques, respectively. The microstructure, density, hardness, and wear rate of the composites were studied. The pin-on-disc method is equipped to study the wear behaviour and coefficient of friction. The sintered density of the prepared Cu-15%Ni is 98.25 %, Cu-8%Sn is 98.20 %, Cu-15%Ni-8%Sn is 98.10 % and Cu-15%Ni-8%Sn-2%B4C is 95.26 % and lower specific wear rate has been recorded for Cu-15Ni-8Sn-2B4C 121×10-6 mm3/(Nm) and the addition of reinforcement B4C in Cu-Ni-Sn displays remarkable changes in wear rate and friction coefficient.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135643594","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}
Random walk of particles during Chladni pattern formation is macroscopically treated as a diffusion process. The corresponding generalized diffusion equation is formulated based upon the generator of vibration driven random walk by following Einstein’s treatment of Brownian motion.
{"title":"Diffusion Equation Generalized for Modeling of Chladni Patterns","authors":"Igor Grabec, Nikolaj Sok","doi":"10.5545/sv-jme.2022.507","DOIUrl":"https://doi.org/10.5545/sv-jme.2022.507","url":null,"abstract":"Random walk of particles during Chladni pattern formation is macroscopically treated as a diffusion process. The corresponding generalized diffusion equation is formulated based upon the generator of vibration driven random walk by following Einstein’s treatment of Brownian motion.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"312 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135643086","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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