In Slovenia, Fe-Si-Al alloys for non-oriented, silicon-steel sheets are designed and manufactured in a sustainable manner. Ferrous scrap is recycled, and, therefore, CO2 emissions are greatly reduced. However, sustainable technologies based on secondary metallurgy have many limitations. Impurities that cannot be effectively removed from the steel melt increase the complexity of the material’s behavior during processing and use. One of the most contaminating elements is copper (Cu). In this review, the focus is on phenomena related to the Cu impurity during the specific steps of the metallurgical processing of selected Fe-Si-Al alloys. The identified challenges concerning the efficiency of some technological phases related to the presence of Cu in Fe-Si-Al, non-oriented electrical steels might motivate further (inter)disciplinary research, basic or applied. In order to follow the set goals of the EU and achieve climate neutrality by 2050, silicon electrical steels produced with sustainable circular-economy approaches must be recognized as a strategic material for the EU.
{"title":"SUSTAINABLE AND STRATEGIC SOFT-MAGNETIC Fe-Si-Al ALLOYS PRODUCED BY SECONDARY METALLURGY","authors":"D. Steiner Petrovič","doi":"10.17222/mit.2023.1072","DOIUrl":"https://doi.org/10.17222/mit.2023.1072","url":null,"abstract":"In Slovenia, Fe-Si-Al alloys for non-oriented, silicon-steel sheets are designed and manufactured in a sustainable manner. Ferrous scrap is recycled, and, therefore, CO2 emissions are greatly reduced. However, sustainable technologies based on secondary metallurgy have many limitations. Impurities that cannot be effectively removed from the steel melt increase the complexity of the material’s behavior during processing and use. One of the most contaminating elements is copper (Cu). In this review, the focus is on phenomena related to the Cu impurity during the specific steps of the metallurgical processing of selected Fe-Si-Al alloys. The identified challenges concerning the efficiency of some technological phases related to the presence of Cu in Fe-Si-Al, non-oriented electrical steels might motivate further (inter)disciplinary research, basic or applied. In order to follow the set goals of the EU and achieve climate neutrality by 2050, silicon electrical steels produced with sustainable circular-economy approaches must be recognized as a strategic material for the EU.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":" 10","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963608","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 order to cut their carbon footprint and promote environmental sustainability, the majority of businesses have now turned towards sustainable practises in their manufacturing processes and supply networks. The use of sustainable materials has drawn a lot of attention recently as a crucial step in accomplishing these goals. Choosing the material that is most suited for a product can be difficult, despite the fact that there are many sustainable materials available. This study uses machine learning – a random forest algorithm and multi-criteria decision analysis (MCDA) to optimise the use of sustainable materials in supply-chain operations. The study uses machine learning algorithms to analyse data on different sustainable materials, their characteristics and their effects on the environment. The study also investigates how an optimised material selection affects the whole supply chain, including the production, packing and shipping operations. The research offers a complete strategy for reducing the environmental effect of industrial processes by combining approaches from material engineering, supply chain management and machine learning. The novelty of this work resides in its integration of material engineering and machine learning strategies to enhance the supply chain choice of sustainable materials. As a notable example, the study highlights the potential of mycelium as a sustainable material for air conditioner components. Mycelium’s unique properties, such as its biodegradability, lightweight nature and adaptability position it as a promising candidate, enhancing the environmental profile of air conditioners. By incorporating mycelium-based components, manufacturers can significantly reduce carbon emissions, resource consumption and waste generation throughout a product’s lifecycle. This investigation underscores both the viability of mycelium and the broader significance of innovative material choices in reshaping industries towards a more sustainable future. Through such advances, this research not only contributes to the air conditioning sector but also establishes a paradigm for sustainable material adoption with far-reaching positive implications.
{"title":"OPTIMIZING SUSTAINABLE MATERIAL SELECTION FOR AIR CONDITIONERS IN A SUPPLY CHAIN","authors":"P. Sivaraman, Santhosh S.","doi":"10.17222/mit.2023.940","DOIUrl":"https://doi.org/10.17222/mit.2023.940","url":null,"abstract":"In order to cut their carbon footprint and promote environmental sustainability, the majority of businesses have now turned towards sustainable practises in their manufacturing processes and supply networks. The use of sustainable materials has drawn a lot of attention recently as a crucial step in accomplishing these goals. Choosing the material that is most suited for a product can be difficult, despite the fact that there are many sustainable materials available. This study uses machine learning – a random forest algorithm and multi-criteria decision analysis (MCDA) to optimise the use of sustainable materials in supply-chain operations. The study uses machine learning algorithms to analyse data on different sustainable materials, their characteristics and their effects on the environment. The study also investigates how an optimised material selection affects the whole supply chain, including the production, packing and shipping operations. The research offers a complete strategy for reducing the environmental effect of industrial processes by combining approaches from material engineering, supply chain management and machine learning. The novelty of this work resides in its integration of material engineering and machine learning strategies to enhance the supply chain choice of sustainable materials. As a notable example, the study highlights the potential of mycelium as a sustainable material for air conditioner components. Mycelium’s unique properties, such as its biodegradability, lightweight nature and adaptability position it as a promising candidate, enhancing the environmental profile of air conditioners. By incorporating mycelium-based components, manufacturers can significantly reduce carbon emissions, resource consumption and waste generation throughout a product’s lifecycle. This investigation underscores both the viability of mycelium and the broader significance of innovative material choices in reshaping industries towards a more sustainable future. Through such advances, this research not only contributes to the air conditioning sector but also establishes a paradigm for sustainable material adoption with far-reaching positive implications.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"20 9","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138979975","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}
SiO2/Ag microbeads were synthesized using the electroless plating method by changing the addition order and the mixed method of electroless plating. Conducting composites were prepared using the prepared SiO2/Ag microbeads and unsaturated polyester resin as the fillers and substrate, respectively. The microstructure and properties of the prepared microbeads and composite were characterized with a scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS), particle size analyzer, DC milliohm meter and vector network analysis tester. Results show that the SiO2/Ag microbeads prepared with the reverse dropping electroless plating method achieved the best uniformity and integrity of the silver coating on the surfaces of glass beads, and its compaction resistance reached 138.80 mΩ·cm. When the ratio of the prepared SiO2/Ag microbeads and unsaturated polyester resin was 1:2, the obtained coating composite had a resistivity of 2.79 × 10–5 Ω·cm, showing good electromagnetic shielding performance.
{"title":"PREPARATION AND PROPERTIES OF SiO2/Ag MICROBEADS USING ELECTROLESS PLATING METHOD","authors":"Congcong Zhang, Xiaolei Su, Jiaqi Yan, Yi Liu","doi":"10.17222/mit.2023.778","DOIUrl":"https://doi.org/10.17222/mit.2023.778","url":null,"abstract":"SiO2/Ag microbeads were synthesized using the electroless plating method by changing the addition order and the mixed method of electroless plating. Conducting composites were prepared using the prepared SiO2/Ag microbeads and unsaturated polyester resin as the fillers and substrate, respectively. The microstructure and properties of the prepared microbeads and composite were characterized with a scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS), particle size analyzer, DC milliohm meter and vector network analysis tester. Results show that the SiO2/Ag microbeads prepared with the reverse dropping electroless plating method achieved the best uniformity and integrity of the silver coating on the surfaces of glass beads, and its compaction resistance reached 138.80 mΩ·cm. When the ratio of the prepared SiO2/Ag microbeads and unsaturated polyester resin was 1:2, the obtained coating composite had a resistivity of 2.79 × 10–5 Ω·cm, showing good electromagnetic shielding performance.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"19 19","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138980305","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 aim of our study was to investigate how different thermal conditions affect the transformation temperatures of two hot-work steels with high thermal conductivity. We focused on two conditions: soft annealing, and quenching and tempering. Soft annealing results in a ferritic steel matrix with spherical carbides, while quenching and tempering result in a fully hardened and tempered martensitic matrix with secondary and tempering carbides. We analysed samples using a simultaneous thermal analysis (STA) and differential scanning calorimetry (DSC) to determine the transformation temperatures. Controlled heating and cooling allowed us to observe the energy changes associated with the phase transformations. The equilibrium temperatures were calculated using the CALPHAD method. Our study investigated the influence of thermal conditions on different transformation temperatures, including solidus/liquidus temperatures, austenite solid transformation temperatures (A1 and A3), austenite solidification temperatures and bainite and/or martensite transformation temperatures. A DSC analysis was used to quantitatively measure the transformation temperatures and energy absorption during the endothermic processes (austenite solid transformation and melting) and to study the energy release during the exothermic processes (solidification and transformation). The results showed that soft annealing reduced the solidification interval and the solidus temperature, while energy absorption increased during melting. Conversely, quenching and tempering reduced the austenite solid transformation temperatures and energy release during solidification, including δ-ferrite solidification.
{"title":"EFFECT OF STEEL’S THERMAL CONDITION ON THE TRANSFORMATION TEMPERATURES OF TWO HOT-WORK TOOL STEELS WITH INCREASED THERMAL CONDUCTIVITY","authors":"T. Balaško, J. Burja, Jožef Medved","doi":"10.17222/mit.2023.902","DOIUrl":"https://doi.org/10.17222/mit.2023.902","url":null,"abstract":"The aim of our study was to investigate how different thermal conditions affect the transformation temperatures of two hot-work steels with high thermal conductivity. We focused on two conditions: soft annealing, and quenching and tempering. Soft annealing results in a ferritic steel matrix with spherical carbides, while quenching and tempering result in a fully hardened and tempered martensitic matrix with secondary and tempering carbides. We analysed samples using a simultaneous thermal analysis (STA) and differential scanning calorimetry (DSC) to determine the transformation temperatures. Controlled heating and cooling allowed us to observe the energy changes associated with the phase transformations. The equilibrium temperatures were calculated using the CALPHAD method. Our study investigated the influence of thermal conditions on different transformation temperatures, including solidus/liquidus temperatures, austenite solid transformation temperatures (A1 and A3), austenite solidification temperatures and bainite and/or martensite transformation temperatures. A DSC analysis was used to quantitatively measure the transformation temperatures and energy absorption during the endothermic processes (austenite solid transformation and melting) and to study the energy release during the exothermic processes (solidification and transformation). The results showed that soft annealing reduced the solidification interval and the solidus temperature, while energy absorption increased during melting. Conversely, quenching and tempering reduced the austenite solid transformation temperatures and energy release during solidification, including δ-ferrite solidification.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"65 11","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138979146","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}
Lu Yao, Yugui Li, Yaohui Song, Haosong Sun, Yibo Lu, Jiayao Wang
We have studied the effects of different solution temperatures and holding times on the microstructure and room-temperature mechanical properties of the alloy using methods such as electron backscatter diffraction, hardness testing and tensile testing. The results showed that the average grain size increased significantly as the solution temperature increased, and many annealing twins appeared in the grains. The fraction of twin boundaries reached its maximum value at 1080 °C. The hardness, yield strength and tensile strength of the alloy decreased with an increase in the solution temperature, but abnormal yielding occurred at 1160 °C. The elongation after fracture and the area reduction increased with an increase in the solution temperature. The fracture morphology of the alloy was irregular, conical, accompanied by a large number of ductile dimples, and the material exhibited typical ductile fracture. At the same time, as the solution temperature increased, the number of dimples on the fracture surface continued to increase, the depth of the dimples gradually increased, and the distribution became more uniform.
我们采用电子反向散射衍射、硬度测试和拉伸测试等方法，研究了不同固溶温度和保温时间对合金微观结构和室温力学性能的影响。结果表明，随着溶液温度的升高，平均晶粒尺寸显著增大，晶粒中出现了许多退火孪晶。孪晶边界的比例在 1080 °C 时达到最大值。合金的硬度、屈服强度和抗拉强度随着固溶温度的升高而降低，但在 1160 °C 时出现异常屈服。随着溶液温度的升高，断裂后的伸长率和面积减小率增加。合金的断口形态为不规则锥形，并伴有大量韧性凹陷，材料表现出典型的韧性断裂。同时，随着溶液温度的升高，断口表面的凹痕数量继续增加，凹痕深度逐渐增大，分布更加均匀。
{"title":"EFFECT OF SOLUTION TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL BEHAVIOR OF THE NICKEL-BASED ALLOY N06625","authors":"Lu Yao, Yugui Li, Yaohui Song, Haosong Sun, Yibo Lu, Jiayao Wang","doi":"10.17222/mit.2023.942","DOIUrl":"https://doi.org/10.17222/mit.2023.942","url":null,"abstract":"We have studied the effects of different solution temperatures and holding times on the microstructure and room-temperature mechanical properties of the alloy using methods such as electron backscatter diffraction, hardness testing and tensile testing. The results showed that the average grain size increased significantly as the solution temperature increased, and many annealing twins appeared in the grains. The fraction of twin boundaries reached its maximum value at 1080 °C. The hardness, yield strength and tensile strength of the alloy decreased with an increase in the solution temperature, but abnormal yielding occurred at 1160 °C. The elongation after fracture and the area reduction increased with an increase in the solution temperature. The fracture morphology of the alloy was irregular, conical, accompanied by a large number of ductile dimples, and the material exhibited typical ductile fracture. At the same time, as the solution temperature increased, the number of dimples on the fracture surface continued to increase, the depth of the dimples gradually increased, and the distribution became more uniform.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"5 8","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138980318","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}
J. Kraner, Kyung Il Kim, B. Kim, Shae K. Kim, Irena Paulin
The combined effects of the reduction ratio and annealing conditions during cold rolling were investigated for the texture and anisotropy of an EN AW-8011A aluminium alloy. To characterize the microstructural and textural differences, a scanning electron microscope with electron back-scattered diffraction was used. To achieve low anisotropy, the three key factors of texture were exposed: a low fraction of deformed grains according to the average grain misorientation, a large amount of random texture components and the equivalent ratio between deformed and recrystallised texture components. The results of crystallographic texture analysis and anisotropy values revealed that the higher ratio of total cold deformation (cold rolling reduction) and the higher ratio of cold deformation after the intermediate annealing were more favourable for the final continuous annealing in terms of decreasing anisotropy. In contrast, the lower ratio of the cold deformation resulted in lower anisotropy when implementing batch annealing.
研究了冷轧过程中的还原率和退火条件对 EN AW-8011A 铝合金的纹理和各向异性的综合影响。为了表征微观结构和纹理差异，使用了带有电子背散射衍射的扫描电子显微镜。为实现低各向异性，暴露了纹理的三个关键因素：根据平均晶粒取向偏差计算的低变形晶粒比例、大量随机纹理成分以及变形和再结晶纹理成分之间的等效比率。结晶纹理分析和各向异性值的结果表明，就各向异性的减小而言，较高的总冷变形比（冷轧减小）和中间退火后较高的冷变形比更有利于最终的连续退火。相反，在实施分批退火时，较低的冷变形比会导致较低的各向异性。
{"title":"RELEVANCE OF COLD-ROLLING TECHNOLOGY FOR THE TEXTURE AND ANISOTROPY OF EN AW-8011A ALUMINUM ALLOYS","authors":"J. Kraner, Kyung Il Kim, B. Kim, Shae K. Kim, Irena Paulin","doi":"10.17222/mit.2023.993","DOIUrl":"https://doi.org/10.17222/mit.2023.993","url":null,"abstract":"The combined effects of the reduction ratio and annealing conditions during cold rolling were investigated for the texture and anisotropy of an EN AW-8011A aluminium alloy. To characterize the microstructural and textural differences, a scanning electron microscope with electron back-scattered diffraction was used. To achieve low anisotropy, the three key factors of texture were exposed: a low fraction of deformed grains according to the average grain misorientation, a large amount of random texture components and the equivalent ratio between deformed and recrystallised texture components. The results of crystallographic texture analysis and anisotropy values revealed that the higher ratio of total cold deformation (cold rolling reduction) and the higher ratio of cold deformation after the intermediate annealing were more favourable for the final continuous annealing in terms of decreasing anisotropy. In contrast, the lower ratio of the cold deformation resulted in lower anisotropy when implementing batch annealing.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"80 5","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138981846","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}
Titanium dioxide is well known as a photoactive material activated under ultraviolet irradiation. It is either employed as a photocatalyst or it exhibits superhydrophilic behavior after obtaining reduced surface energy under illumination used for self-cleaning or anti-fogging surfaces. For increasing the reactivity of thin films under solar illumination, a reduced band gap is desired. Doping with transition metals or nitrogen has been reported in the literature. However, the incorporation of nitrogen into a growing film is a much more complex process that is presently not completely understood. TiO2 thin layers were produced by metal plasma immersion ion implantation and deposition at room temperature at a pulse voltage of 0–5 kV and a duty cycle of 9 % for an apparently amorphous layer. An auxiliary rf plasma source was employed to increase the growth rate at low gas flow ratios. By adjusting the geometry between the incident ion beam, sputter target and substrate independently of the primary ion energy and species, a controlled deposition of samples was possible. Conventional ion implantation was employed to implant either carbon or nitrogen ions below the surface for bandgap engineering. The resulting thin films were subsequently investigated for optical properties, stoichiometry, structural properties, surface topography and photoactivity.
{"title":"INFLUENCE OF DOPING WITH CARBON AND NITROGEN ON THE PHOTOACTIVITY OF TiO2 THIN FILMS OBTAINED WITH MePIIID","authors":"A. Gjevori, B. Ziberi","doi":"10.17222/mit.2023.867","DOIUrl":"https://doi.org/10.17222/mit.2023.867","url":null,"abstract":"Titanium dioxide is well known as a photoactive material activated under ultraviolet irradiation. It is either employed as a photocatalyst or it exhibits superhydrophilic behavior after obtaining reduced surface energy under illumination used for self-cleaning or anti-fogging surfaces. For increasing the reactivity of thin films under solar illumination, a reduced band gap is desired. Doping with transition metals or nitrogen has been reported in the literature. However, the incorporation of nitrogen into a growing film is a much more complex process that is presently not completely understood. TiO2 thin layers were produced by metal plasma immersion ion implantation and deposition at room temperature at a pulse voltage of 0–5 kV and a duty cycle of 9 % for an apparently amorphous layer. An auxiliary rf plasma source was employed to increase the growth rate at low gas flow ratios. By adjusting the geometry between the incident ion beam, sputter target and substrate independently of the primary ion energy and species, a controlled deposition of samples was possible. Conventional ion implantation was employed to implant either carbon or nitrogen ions below the surface for bandgap engineering. The resulting thin films were subsequently investigated for optical properties, stoichiometry, structural properties, surface topography and photoactivity.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"11 2","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138982073","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}
A. Saiyathibrahim, S. Santhosh, G. Raja Kumar, S. Bharani Kumar
Despite the growing demand for new materials, we used the horizontal centrifugal casting technique to synthesize functionally graded composite (FGC) tubes using an LM6 alloy containing (3, 6 and 9) w/% nickel. All the fabricated tubes were evaluated for variations in microstructure, hardness and tensile properties along the radial cross-section in three distinct zones (inner, transition and outer). X-Ray diffraction (XRD) results indicated the formation of in-situ Al3Ni in all FGC tubes, and these in-situ tri-aluminides increased further with the addition of Ni. A comprehensive microstructural analysis across the tubes utilising scanning electron microscopy (SEM) images showed that gathering in-situ Al3Ni particles keeps growing nearer the outer zone, and primary Si cuboids increase in the inner zone. This accumulation of particles improved the mechanical properties at all three zones of the FGC tubes compared to the LM6 tube having no nickel. The results of the hardness investigation showed that precipitated Al3Ni in FGCs has a beneficial impact on the enhancement of hardness. Furthermore, the observed UTS improvement in the FGC tubes was clearly associated with the precipitation and strengthening action of Al3Ni intermetallic phases, while a significant reduction in elongation has been noted. Due to the influence of centrifugal force and density variation, the tube containing 9 w/% of Ni demonstrated good gradation among composite alloy-fabricated FGC tubes, with in-situ Al3Ni particles settling largely in the outer zone and primary Si particles settling primarily in the inner zone across the radial thickness.
{"title":"INFLUENCE OF NICKEL ON THE MICROSTRUCTURAL EVOLUTION AND MECHANICAL PROPERTIES OF LM6-ALLOY-BASED FUNCTIONALLY GRADED COMPOSITE TUBES","authors":"A. Saiyathibrahim, S. Santhosh, G. Raja Kumar, S. Bharani Kumar","doi":"10.17222/mit.2023.799","DOIUrl":"https://doi.org/10.17222/mit.2023.799","url":null,"abstract":"Despite the growing demand for new materials, we used the horizontal centrifugal casting technique to synthesize functionally graded composite (FGC) tubes using an LM6 alloy containing (3, 6 and 9) w/% nickel. All the fabricated tubes were evaluated for variations in microstructure, hardness and tensile properties along the radial cross-section in three distinct zones (inner, transition and outer). X-Ray diffraction (XRD) results indicated the formation of in-situ Al3Ni in all FGC tubes, and these in-situ tri-aluminides increased further with the addition of Ni. A comprehensive microstructural analysis across the tubes utilising scanning electron microscopy (SEM) images showed that gathering in-situ Al3Ni particles keeps growing nearer the outer zone, and primary Si cuboids increase in the inner zone. This accumulation of particles improved the mechanical properties at all three zones of the FGC tubes compared to the LM6 tube having no nickel. The results of the hardness investigation showed that precipitated Al3Ni in FGCs has a beneficial impact on the enhancement of hardness. Furthermore, the observed UTS improvement in the FGC tubes was clearly associated with the precipitation and strengthening action of Al3Ni intermetallic phases, while a significant reduction in elongation has been noted. Due to the influence of centrifugal force and density variation, the tube containing 9 w/% of Ni demonstrated good gradation among composite alloy-fabricated FGC tubes, with in-situ Al3Ni particles settling largely in the outer zone and primary Si particles settling primarily in the inner zone across the radial thickness.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"127 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138978627","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}
A smartphone battery can be charged without an external power source by applying a portable charger that transforms mechanical energy into electricity by means of magnetic induction. Its essential part is a permanent magnet made of a rather expensive and, from the point of view of availability as well ecology, problematic material. The magnet is usually assembled from cylindrical parts. In order to reduce the raw-material consumption and to simplify the production, we propose a single-piece design in the form of a cylinder with notches. By means of the finite-element modelling, we optimize the dimensional parameters and prove that our proposal is more efficient than standard solutions.
{"title":"OPTIMUM DESIGN OF A PERMANENT-MAGNET-BASED SELF-CHARGING DEVICE FOR A SMARTPHONE","authors":"Anubhav Vishwakarma, Matej Komelj","doi":"10.17222/mit.2023.968","DOIUrl":"https://doi.org/10.17222/mit.2023.968","url":null,"abstract":"A smartphone battery can be charged without an external power source by applying a portable charger that transforms mechanical energy into electricity by means of magnetic induction. Its essential part is a permanent magnet made of a rather expensive and, from the point of view of availability as well ecology, problematic material. The magnet is usually assembled from cylindrical parts. In order to reduce the raw-material consumption and to simplify the production, we propose a single-piece design in the form of a cylinder with notches. By means of the finite-element modelling, we optimize the dimensional parameters and prove that our proposal is more efficient than standard solutions.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"16 5","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138979031","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}
Mengmeng Li, Hongchao Ji, Chun Han, Shengqiang Liu, Wenchao Xiao
The corrosion behavior of galvanized X80 pipeline steel welded joints in a marine atmospheric environment was studied using the cyclic salt spray accelerated corrosion test. The corrosion weight loss, corrosion morphology and corrosion products of samples under different cycles were characterized by means of appearance inspection, SEM and EDS. The results show that with the rupture of the galvanized layer, cracks first appear when the weld metal is exposed for eight days. With the infiltration of the corrosive liquid, pitting pits first appear in the weld metal. In the early stage of corrosion in the heat-affected zone, the fracture degree of the zinc layer is more serious than that in the other two areas. The corrosion products of the zinc layer accumulate irregularly and more pits appear, resulting in early cracks and pitting pits in the later stage. Compared with the first two regions, the base metal shows better corrosion resistance.
{"title":"STUDY ON THE ACCELERATED CORROSION BEHAVIOR OF A GALVANIZED X80 PIPELINE STEEL WELDED JOINT DURING A CYCLIC SALT SPRAY TEST","authors":"Mengmeng Li, Hongchao Ji, Chun Han, Shengqiang Liu, Wenchao Xiao","doi":"10.17222/mit.2023.946","DOIUrl":"https://doi.org/10.17222/mit.2023.946","url":null,"abstract":"The corrosion behavior of galvanized X80 pipeline steel welded joints in a marine atmospheric environment was studied using the cyclic salt spray accelerated corrosion test. The corrosion weight loss, corrosion morphology and corrosion products of samples under different cycles were characterized by means of appearance inspection, SEM and EDS. The results show that with the rupture of the galvanized layer, cracks first appear when the weld metal is exposed for eight days. With the infiltration of the corrosive liquid, pitting pits first appear in the weld metal. In the early stage of corrosion in the heat-affected zone, the fracture degree of the zinc layer is more serious than that in the other two areas. The corrosion products of the zinc layer accumulate irregularly and more pits appear, resulting in early cracks and pitting pits in the later stage. Compared with the first two regions, the base metal shows better corrosion resistance.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"6 5","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138980298","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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