Salem Ibrahim Shwika, Kaled Mohamed Benomran, Natalija Čutović, A. Marinković, M. Ranitović, Dragana Vasilski, Ž. Kamberović
Due to the rapidly increasing use of electrical devices, e-waste became one of the major threats to the environment. Waste printed circuit boards (WPCBs) are an integral part of electrical devices, thus the interest in their recycling is growing. Recycling of WPCBs can be performed by applying hydrometallurgical or pyrometallurgical processes, as well as vacuum pyrolysis. The main advantages of vacuum pyrolysis are eco-friendliness, economic viability and efficiency in extracting present noble metals, while pyrolysis oil occurs as a by-product. Pyrolysis oil poses a tremendous threat to the environment, due to the possibility of its spillage into water, as well as a potential release into the air and soil. Because of this, the pyrolysis oil was subjected to chemical treatment with different reagents, such as sodium hydroxide, calcium oxide, sulfuric acid and maleic anhydride, with the intent to solidify the material and remove unpleasant odors. Incorporation of the solidified materials into bitumen, at 2.5, 5, 7.5, and 10 wt.% addition, was performed to obtain waterproofing materials. The obtained solidified and bituminous water-resistant materials were subjected to various test methods: FTIR spectroscopy, physicochemical and mechanical properties of bitumen, etc. which showed that all the tested characteristics are in accordance with values prescribed by the current standard. Toxicity Leaching Procedure (TCLP) confirmed non-hazardous characteristics of the obtained materials, except for the ones with added solidified pyrolysis oil, with Sodium hydroxide, that showed higher leaching of the phenol constituent.
{"title":"Sustainable development in WPCBs treatment for production of bituminous waterproofing materials","authors":"Salem Ibrahim Shwika, Kaled Mohamed Benomran, Natalija Čutović, A. Marinković, M. Ranitović, Dragana Vasilski, Ž. Kamberović","doi":"10.30544/787","DOIUrl":"https://doi.org/10.30544/787","url":null,"abstract":"Due to the rapidly increasing use of electrical devices, e-waste became one of the major threats to the environment. Waste printed circuit boards (WPCBs) are an integral part of electrical devices, thus the interest in their recycling is growing. Recycling of WPCBs can be performed by applying hydrometallurgical or pyrometallurgical processes, as well as vacuum pyrolysis. The main advantages of vacuum pyrolysis are eco-friendliness, economic viability and efficiency in extracting present noble metals, while pyrolysis oil occurs as a by-product. Pyrolysis oil poses a tremendous threat to the environment, due to the possibility of its spillage into water, as well as a potential release into the air and soil. Because of this, the pyrolysis oil was subjected to chemical treatment with different reagents, such as sodium hydroxide, calcium oxide, sulfuric acid and maleic anhydride, with the intent to solidify the material and remove unpleasant odors. Incorporation of the solidified materials into bitumen, at 2.5, 5, 7.5, and 10 wt.% addition, was performed to obtain waterproofing materials. The obtained solidified and bituminous water-resistant materials were subjected to various test methods: FTIR spectroscopy, physicochemical and mechanical properties of bitumen, etc. which showed that all the tested characteristics are in accordance with values prescribed by the current standard. Toxicity Leaching Procedure (TCLP) confirmed non-hazardous characteristics of the obtained materials, except for the ones with added solidified pyrolysis oil, with Sodium hydroxide, that showed higher leaching of the phenol constituent.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83508732","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 research work carried out friction stir welding (FSW) of dissimilar aluminum AA3003-H12 and copper C12200-H01, with wide application in the refrigeration and heat exchanger industry. The main aim of this study is to investigate the influence of process parameters, i.e. pin type (PT), weld speed (WS), rotational speed (RPM), and shoulder diameter (SD) on impact energy (IE) of Al-Cu welded joint. The experimental study used the full factorial method with mixed levels of process parameters. Analysis of Variance (ANOVA) determines the significance of process parameters on impact energy. The results of the analysis of variance (ANOVA) shows that rotational speed (RPM) is the most influential process parameter contributing to the impact energy (IE) of dissimilar Al-Cu weld joint. The response optimizer tool in Minitab 18 software gives optimum weld conditions of process parameters for better weld performance. The FSW experiment with a tapered pin, weld speed of 16 mm/min, rotational speed of 1120 rpm, and shoulder diameter of 22.5 mm obtained the maximum impact energy value of 6.5367 J. The fine-grain recrystallization formed intermetallic compounds in the stir zone (SZ). These intermetallic compounds give a maximum microhardness of 382.24 Hv (0.1). The microstructure analysis of the stir zone (SZ) shows an equiaxed grain structure on the Cu side, while the Al side shows a fine recrystallized grain structure.
{"title":"Experimental investigation on impact energy of friction stir welded aluminum and copper dissimilar joint using full factorial method","authors":"G. Shinde, Dr.Rachayya. R Arakerimath","doi":"10.30544/738","DOIUrl":"https://doi.org/10.30544/738","url":null,"abstract":"This research work carried out friction stir welding (FSW) of dissimilar aluminum AA3003-H12 and copper C12200-H01, with wide application in the refrigeration and heat exchanger industry. The main aim of this study is to investigate the influence of process parameters, i.e. pin type (PT), weld speed (WS), rotational speed (RPM), and shoulder diameter (SD) on impact energy (IE) of Al-Cu welded joint. The experimental study used the full factorial method with mixed levels of process parameters. Analysis of Variance (ANOVA) determines the significance of process parameters on impact energy. The results of the analysis of variance (ANOVA) shows that rotational speed (RPM) is the most influential process parameter contributing to the impact energy (IE) of dissimilar Al-Cu weld joint. The response optimizer tool in Minitab 18 software gives optimum weld conditions of process parameters for better weld performance. The FSW experiment with a tapered pin, weld speed of 16 mm/min, rotational speed of 1120 rpm, and shoulder diameter of 22.5 mm obtained the maximum impact energy value of 6.5367 J. The fine-grain recrystallization formed intermetallic compounds in the stir zone (SZ). These intermetallic compounds give a maximum microhardness of 382.24 Hv (0.1). The microstructure analysis of the stir zone (SZ) shows an equiaxed grain structure on the Cu side, while the Al side shows a fine recrystallized grain structure.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78808606","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}
Kaled Mohamed Benomran, Salem Ibrahim Shwika, M. Vuksanović, A. Marinković, Aleksandar Jovanović, N. Prlainović, Dragana Vasilski
During a fire, passive fire protection systems are designed to prevent the spread of flames, smoke, and toxic gases. The new fire-retardant (FR) material, used for passive fire protection, is created by combining copolymers (VC–co–VAc) (Slovinyl KV 173) and PVC K70 with expanded graphite and plasticizers/modifiers such as diisononyl phthalate - DINP, diisononyl terephthalate - DINTP, dioctyl adipate - DOA, as well as plasticizers that are synthesized based on tertiary recycling of waste poly(ethylene terephthalate) (PET), 1-hexadecene, azodicarbonamide (ADC), tri(p-cresyl phosphate), epoxidized soybean oil (ESO) and acrylate emulsion (DH50, Ecrylic, or Flexryl, etc.). The obtained material's morphology was examined using an emission scanning electron microscope (FESEM) field. Tensile testing was used to determine the mechanical properties of the obtained samples, as well as Shore A hardness and toughness using the Charpy impact test. All samples obtained were tested according to non-flammability standards. To conform to the new trend of "green economy," the development of novel eco-friendly FRs with improved thermal and mechanical properties will include careful consideration of environmental protection and sustainable development.
{"title":"Circular economy implementation in the development of fire-retardant materials used in construction, industry, and general-purpose products","authors":"Kaled Mohamed Benomran, Salem Ibrahim Shwika, M. Vuksanović, A. Marinković, Aleksandar Jovanović, N. Prlainović, Dragana Vasilski","doi":"10.30544/768","DOIUrl":"https://doi.org/10.30544/768","url":null,"abstract":"During a fire, passive fire protection systems are designed to prevent the spread of flames, smoke, and toxic gases. The new fire-retardant (FR) material, used for passive fire protection, is created by combining copolymers (VC–co–VAc) (Slovinyl KV 173) and PVC K70 with expanded graphite and plasticizers/modifiers such as diisononyl phthalate - DINP, diisononyl terephthalate - DINTP, dioctyl adipate - DOA, as well as plasticizers that are synthesized based on tertiary recycling of waste poly(ethylene terephthalate) (PET), 1-hexadecene, azodicarbonamide (ADC), tri(p-cresyl phosphate), epoxidized soybean oil (ESO) and acrylate emulsion (DH50, Ecrylic, or Flexryl, etc.). The obtained material's morphology was examined using an emission scanning electron microscope (FESEM) field. Tensile testing was used to determine the mechanical properties of the obtained samples, as well as Shore A hardness and toughness using the Charpy impact test. All samples obtained were tested according to non-flammability standards. To conform to the new trend of \"green economy,\" the development of novel eco-friendly FRs with improved thermal and mechanical properties will include careful consideration of environmental protection and sustainable development.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85855646","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}
In this paper, a study is conducted to determine numerically the effect of the nanoparticles nature (Al2O3, CuO, and Fe3O4) on the thermo-magnetohydrodynamic behavior of a nanofluid in a square cavity with a circular obstacle. The left wall of this cavity is movable and provided with a cold temperature (Tc) and the right wall is exposed to a hot temperature (Th). However, the upper and lower walls are considered adiabatic. The purpose of this paper is to highlight the effect of aluminum dioxide, copper oxide, and iron trioxide nanoparticles on the thermal and hydrodynamic behavior under the influence of different volume fractions(0 ≤ φ ≤ 0.1), different Hartmann numbers (0 ≤ Ha ≤ 75) and Richardson number (0 ≤ Ri ≤5). The system of governing équations was solved by the finite element method adopting the Galerkine discretization. The obtained results showed that the CuO nanoparticles improve the heat transfer at the fluid and obstacle, in addition, the increase of Hartmann number reduces the heat capacity, especially with the use of Fe3O4 nanoparticles. This study falls within the context of improving the cooling rate of industrial equipment.
{"title":"Numerical investigation of the nanoparticles nature effect on the mhd behavior in a square cavity with a metallic obstacle","authors":"Fayçal Bouzit, M. Bouzit, Abderrahim Mokhefi","doi":"10.30544/725","DOIUrl":"https://doi.org/10.30544/725","url":null,"abstract":"In this paper, a study is conducted to determine numerically the effect of the nanoparticles nature (Al2O3, CuO, and Fe3O4) on the thermo-magnetohydrodynamic behavior of a nanofluid in a square cavity with a circular obstacle. The left wall of this cavity is movable and provided with a cold temperature (Tc) and the right wall is exposed to a hot temperature (Th). However, the upper and lower walls are considered adiabatic. The purpose of this paper is to highlight the effect of aluminum dioxide, copper oxide, and iron trioxide nanoparticles on the thermal and hydrodynamic behavior under the influence of different volume fractions(0 ≤ φ ≤ 0.1), different Hartmann numbers (0 ≤ Ha ≤ 75) and Richardson number (0 ≤ Ri ≤5). The system of governing équations was solved by the finite element method adopting the Galerkine discretization. The obtained results showed that the CuO nanoparticles improve the heat transfer at the fluid and obstacle, in addition, the increase of Hartmann number reduces the heat capacity, especially with the use of Fe3O4 nanoparticles. This study falls within the context of improving the cooling rate of industrial equipment.\u0000 ","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"70 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90716972","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}
Sintered composites have revolutionized as a thermal treatment to consolidate a wide range of engineering materials where the transition of powders takes place thermally in a thermodynamical equilibrium state with a decrease in free surface energy in materials owing to their specific capability. Sintering aids in providing effective bonding between the reinforced powder particles. However, the inadequate understanding of the sintering mechanism may limit the practical application of a few materials such as aluminum metal matrix composites. In addition to the rapid growth of various sintering related technologies, researchers need attention to highlight the structural barriers and forecast the emerging demands while dealing with such composites. A review report is made in this paper regarding the sintering mechanisms and sintering techniques. Common sintering techniques such as traditional, microwave assisted, hot pressing, hot isostatic sintering, and spark plasma sintering are identified and discussed here. As a result, the key challenges in sintering aluminium metal matrix composites that can affect sintering parameters are investigated. From the review, spark plasma is identified to attain densified and pore-free green composites and, microwave sintering is the best technique for achieving uniform microstructure in powder metallurgy samples.
{"title":"An overview on the microstructure and mechanical properties of sintered aluminum-based composites","authors":"Shoba Chintada, Siva Prasad Dora, Dorathi Kare","doi":"10.30544/687","DOIUrl":"https://doi.org/10.30544/687","url":null,"abstract":"Sintered composites have revolutionized as a thermal treatment to consolidate a wide range of engineering materials where the transition of powders takes place thermally in a thermodynamical equilibrium state with a decrease in free surface energy in materials owing to their specific capability. Sintering aids in providing effective bonding between the reinforced powder particles. However, the inadequate understanding of the sintering mechanism may limit the practical application of a few materials such as aluminum metal matrix composites. In addition to the rapid growth of various sintering related technologies, researchers need attention to highlight the structural barriers and forecast the emerging demands while dealing with such composites. A review report is made in this paper regarding the sintering mechanisms and sintering techniques. Common sintering techniques such as traditional, microwave assisted, hot pressing, hot isostatic sintering, and spark plasma sintering are identified and discussed here. As a result, the key challenges in sintering aluminium metal matrix composites that can affect sintering parameters are investigated. From the review, spark plasma is identified to attain densified and pore-free green composites and, microwave sintering is the best technique for achieving uniform microstructure in powder metallurgy samples.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87883679","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. Ibrahim, Abdullah Hamad Singal, Diana Abed al kareem Noori
Electrode Discharge Mechanism (EDM) is a manufacturing process using controlled sparks that occur between an electrically conductive workpiece and an electrode in the presence of an insulating liquid. The EDM process is commonly used to manufacture metallic matrix compounds that have wide applications in the railway sectors and the aircraft industry. Aluminum metal matrix composites (AMMCs) are one of the important kinds of metallic matrix compounds due to their advanced characteristics, such as lightweight and high strength. This lightweight material was developed and used in various manufacturing processes, like the automobile industry to reduce vehicle weight and thus reduce fuel consumption. This paper discussed the experiments of the EDM that were conducted to examine the effect of machining parameters, including peak current (10, 20, and 30 A), pulse on different times (50, 100, and 200 µsec), duty factors (4, 6, and 8) on the material removal rate, and surface roughness of the Al (6061)-5%SiC-10%B4C hybrid composite as workpiece using copper electrode tool by Box-Behnken design. The analysis data for the dependent and independent variables manifested that the influence of machine parameters whenever Ip and Pon increase, the MRR and Ra increase.
{"title":"Investigation of material removal rate and surface roughness during electrical discharge machining on Al (6061)-5%SiC-10%B4C hybrid composite","authors":"A. Ibrahim, Abdullah Hamad Singal, Diana Abed al kareem Noori","doi":"10.30544/798","DOIUrl":"https://doi.org/10.30544/798","url":null,"abstract":"Electrode Discharge Mechanism (EDM) is a manufacturing process using controlled sparks that occur between an electrically conductive workpiece and an electrode in the presence of an insulating liquid. The EDM process is commonly used to manufacture metallic matrix compounds that have wide applications in the railway sectors and the aircraft industry. Aluminum metal matrix composites (AMMCs) are one of the important kinds of metallic matrix compounds due to their advanced characteristics, such as lightweight and high strength. This lightweight material was developed and used in various manufacturing processes, like the automobile industry to reduce vehicle weight and thus reduce fuel consumption. This paper discussed the experiments of the EDM that were conducted to examine the effect of machining parameters, including peak current (10, 20, and 30 A), pulse on different times (50, 100, and 200 µsec), duty factors (4, 6, and 8) on the material removal rate, and surface roughness of the Al (6061)-5%SiC-10%B4C hybrid composite as workpiece using copper electrode tool by Box-Behnken design. The analysis data for the dependent and independent variables manifested that the influence of machine parameters whenever Ip and Pon increase, the MRR and Ra increase.\u0000 ","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"254 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73220832","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}
Ravikumar Mukundaiah, Reddappa H N, S. R, R. Y. S., Babu E R, Nagaraja C Reddy
In the present research, the effects of volume fraction of SiC+Al2O3 particles and aging temperature on the machinability of stir-casted Al7075 metal matrix composites (MMC) have been investigated. The hybrid composites were fabricated using the liquid metallurgy route. Al7075 was reinforced with different wt. % of SiC (3%, 6%, and 9%) and Al2O3 (2%, 4%, and 6%) which were used to fabricate the hybrid metal matrix composites. The samples were aged at different temperatures (140 ºC, 160 ºC, and 180 ºC) for 4 h and cooled at furnace temperature (27 ºC). The machinability of hybrid metal matrix composites was studied by carrying out L27 orthogonal array experiments. Three process parameters were selected, such as 0.2 mm/min of the depth of cut, 0.1 mm/min of feed rate, and 1500 rpm of spindle speed. The obtained results indicate that the surface roughness and machining force of MMCs increase with an increase in weight percentage of Al2O3/SiC and decrease with the increase in aging temperature. Optimum machining force and surface roughness were obtained at 2% Al2O3 + 3 % SiC and 180°C of aging temperature.
{"title":"Machinability study on Al7075/Al2O3-SiC hybrid composites","authors":"Ravikumar Mukundaiah, Reddappa H N, S. R, R. Y. S., Babu E R, Nagaraja C Reddy","doi":"10.30544/749","DOIUrl":"https://doi.org/10.30544/749","url":null,"abstract":"In the present research, the effects of volume fraction of SiC+Al2O3 particles and aging temperature on the machinability of stir-casted Al7075 metal matrix composites (MMC) have been investigated. The hybrid composites were fabricated using the liquid metallurgy route. Al7075 was reinforced with different wt. % of SiC (3%, 6%, and 9%) and Al2O3 (2%, 4%, and 6%) which were used to fabricate the hybrid metal matrix composites. The samples were aged at different temperatures (140 ºC, 160 ºC, and 180 ºC) for 4 h and cooled at furnace temperature (27 ºC). The machinability of hybrid metal matrix composites was studied by carrying out L27 orthogonal array experiments. Three process parameters were selected, such as 0.2 mm/min of the depth of cut, 0.1 mm/min of feed rate, and 1500 rpm of spindle speed. The obtained results indicate that the surface roughness and machining force of MMCs increase with an increase in weight percentage of Al2O3/SiC and decrease with the increase in aging temperature. Optimum machining force and surface roughness were obtained at 2% Al2O3 + 3 % SiC and 180°C of aging temperature.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80485899","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}
In this work lightweight expanded perlite/sodium silicate composite foams were manufactured with varying quantities of boric acid (BA) 0-2.88 wt.%. The composites were characterized for density, compressive strength (CS), compressive modulus (CM), and energy absorption (EA) up to 50% strain. The compression tests were also conducted at various crosshead speeds to evaluate the strain rate dependency of the foams. The hygroscopic tests were done to evaluate water absorption properties and investigate the effects of water absorption on the compressive properties of the foams. The CS, CM, and EA of the foams increased for a boric acid content of 0.74 wt.%, but further addition of BA caused a gradual decrease in these characteristics. The range of sp. CS (3.80-5.93 MPa/(g/cm3)) achieved were found to be well compatible with the values of building materials in the literature. The foams appeared to be sensitive to the strain rate in compression, causing variations in the compressive properties as well as the trends of stress-strain curves. Furthermore, the addition of BA in the composite reduced water absorption up to a BA content of 1.46 wt.%. The compressive properties were also highly influenced by the hygrometric test.
{"title":"Compressive behavior of perlite/sodium silicate composite foam modified by boric acid","authors":"Pranto Karua, M. Arifuzzaman","doi":"10.30544/755","DOIUrl":"https://doi.org/10.30544/755","url":null,"abstract":"In this work lightweight expanded perlite/sodium silicate composite foams were manufactured with varying quantities of boric acid (BA) 0-2.88 wt.%. The composites were characterized for density, compressive strength (CS), compressive modulus (CM), and energy absorption (EA) up to 50% strain. The compression tests were also conducted at various crosshead speeds to evaluate the strain rate dependency of the foams. The hygroscopic tests were done to evaluate water absorption properties and investigate the effects of water absorption on the compressive properties of the foams. The CS, CM, and EA of the foams increased for a boric acid content of 0.74 wt.%, but further addition of BA caused a gradual decrease in these characteristics. The range of sp. CS (3.80-5.93 MPa/(g/cm3)) achieved were found to be well compatible with the values of building materials in the literature. The foams appeared to be sensitive to the strain rate in compression, causing variations in the compressive properties as well as the trends of stress-strain curves. Furthermore, the addition of BA in the composite reduced water absorption up to a BA content of 1.46 wt.%. The compressive properties were also highly influenced by the hygrometric test.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90037832","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}
H. K. Vuddagiri, Sivasankara Raju Rallabandi, S. Vadapalli, T. Pandi
This work emphasizes the mechanical and tribological performance of Al-Si/Al2O3/MoS2 hybrid matrix composites. The composites are reinforced by varying weight percentages of Al2O3 (8%, 12%, and 16%) and MoS2 (0%, 2%, and 4%), and were prepared by stir casting. As the weight percentage of Al2O3 in a composite grows, so does its hardness and tensile strength. The addition of 2% wt. MoS2 enhances the specific strength and tribological properties, according to the research. However, when compared to other composites studied, the Al/16% Al2O3 composite had improved mechanical properties. MoS2 also aids the hybrid composite in achieving higher tribological characteristics while marginally lowering the specific strength. Taguchi orthogonal array (L27) is used to design tribological performances with process parameters viz. applied load, sliding speed and weight % of Al2O3 as well the percentage of MoS2 whereas wear rate (mm3/m), wear (µm) and coefficient of friction were considered as the responses. A hybrid Grey–Fuzzy Reasoning Approach (GFRA) is used to optimize a multi-response for avoiding vagueness in decision making. The statistical analysis revealed that Al/2%MoS2/16%Al2O3 composite has exhibited better wear resistance than other composites. The confirmation test is also conducted to validate the optimal condition obtained by ANOVA.
{"title":"Assessment of mechanical and tribological performance of hybrid Al/MoS2/Al2O3 composite by GFRA","authors":"H. K. Vuddagiri, Sivasankara Raju Rallabandi, S. Vadapalli, T. Pandi","doi":"10.30544/764","DOIUrl":"https://doi.org/10.30544/764","url":null,"abstract":"This work emphasizes the mechanical and tribological performance of Al-Si/Al2O3/MoS2 hybrid matrix composites. The composites are reinforced by varying weight percentages of Al2O3 (8%, 12%, and 16%) and MoS2 (0%, 2%, and 4%), and were prepared by stir casting. As the weight percentage of Al2O3 in a composite grows, so does its hardness and tensile strength. The addition of 2% wt. MoS2 enhances the specific strength and tribological properties, according to the research. However, when compared to other composites studied, the Al/16% Al2O3 composite had improved mechanical properties. MoS2 also aids the hybrid composite in achieving higher tribological characteristics while marginally lowering the specific strength. Taguchi orthogonal array (L27) is used to design tribological performances with process parameters viz. applied load, sliding speed and weight % of Al2O3 as well the percentage of MoS2 whereas wear rate (mm3/m), wear (µm) and coefficient of friction were considered as the responses. A hybrid Grey–Fuzzy Reasoning Approach (GFRA) is used to optimize a multi-response for avoiding vagueness in decision making. The statistical analysis revealed that Al/2%MoS2/16%Al2O3 composite has exhibited better wear resistance than other composites. The confirmation test is also conducted to validate the optimal condition obtained by ANOVA.\u0000 ","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90272199","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. Bošnjaković, Mladen Bugarčić, Natalija Čutović, Aleksandar Jovanović, S. Manasijevic, A. Marinković, Z. Veličković
Elderberry (Sambucus nigra) pith was modified with polyethyleneimine (PEI) in order to improve the adsorption properties. Characterization of both dried Sambucus nigra pith (DSNP) and amino modification of elderberry pith with branched PEI (PEI/DSNP) was performed by: Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and porosity determination. The amine and ester number, as well as acid value, were determined on DSNP and PEI/DSNP samples using standard volumetric methods. The samples were used as adsorbents for Pb2+ ions from an aqueous solution in a batch system. The obtained results were fitted using suitable equilibrium isotherm and kinetic models. The maximum adsorption capacity for Pb2+ ions on DSNP and aminаted sample, obtained using Langmuir adsorption isotherm at 298 K, are 18.9 and 47.8 mg g-1, respectively. Based on the kinetic studies, the adsorption process follows the pseudo second-order model. Thermodynamic parameters showed that the adsorption process is endothermic and spontaneous. In general, the overall adsorption process was improved by modifying starting material with branched PEI modifier by introducing large numbers of amino functionalities having high affinity to cations.
{"title":"Eco-friendly Elderberry based sorbent for removing Pb2+ ions from aqueous solutions","authors":"J. Bošnjaković, Mladen Bugarčić, Natalija Čutović, Aleksandar Jovanović, S. Manasijevic, A. Marinković, Z. Veličković","doi":"10.30544/710","DOIUrl":"https://doi.org/10.30544/710","url":null,"abstract":"Elderberry (Sambucus nigra) pith was modified with polyethyleneimine (PEI) in order to improve the adsorption properties. Characterization of both dried Sambucus nigra pith (DSNP) and amino modification of elderberry pith with branched PEI (PEI/DSNP) was performed by: Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and porosity determination. The amine and ester number, as well as acid value, were determined on DSNP and PEI/DSNP samples using standard volumetric methods. The samples were used as adsorbents for Pb2+ ions from an aqueous solution in a batch system. The obtained results were fitted using suitable equilibrium isotherm and kinetic models. The maximum adsorption capacity for Pb2+ ions on DSNP and aminаted sample, obtained using Langmuir adsorption isotherm at 298 K, are 18.9 and 47.8 mg g-1, respectively. Based on the kinetic studies, the adsorption process follows the pseudo second-order model. Thermodynamic parameters showed that the adsorption process is endothermic and spontaneous. In general, the overall adsorption process was improved by modifying starting material with branched PEI modifier by introducing large numbers of amino functionalities having high affinity to cations.","PeriodicalId":18466,"journal":{"name":"Metallurgical and Materials Engineering","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88926530","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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