Search2023 Vol. 30, No. 6
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2023, vol. 30, no. 6, pp.
989-1002.
https://doi.org/10.1007/s12613-022-2552-y
Abstract:
Copper–indium–gallium–diselenide (CIGS) is a fast-evolving commercial solar cell. The firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGS solar cell recycling. In this paper, the sources and characteristics of valuable metals in spent CIGS solar cells were reviewed. The potential environmental impacts of CIGS, including service life, critical material, and material toxicity, were outlined. The main recovery methods of valuable metals in the various types of spent CIGS, including hydrometallurgy, pyrometallurgy, and comprehensive treatment processes, were compared and discussed. The mechanism of different recovery processes was summarized. The challenges faced by different recycling processes of spent CIGS were also covered in this review. Finally, the economic viability of the recycling process was assessed. The purpose of this review is to provide reasonable suggestions for the sustainable development of CIGS and the harmless disposal of spent CIGS.
Copper–indium–gallium–diselenide (CIGS) is a fast-evolving commercial solar cell. The firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGS solar cell recycling. In this paper, the sources and characteristics of valuable metals in spent CIGS solar cells were reviewed. The potential environmental impacts of CIGS, including service life, critical material, and material toxicity, were outlined. The main recovery methods of valuable metals in the various types of spent CIGS, including hydrometallurgy, pyrometallurgy, and comprehensive treatment processes, were compared and discussed. The mechanism of different recovery processes was summarized. The challenges faced by different recycling processes of spent CIGS were also covered in this review. Finally, the economic viability of the recycling process was assessed. The purpose of this review is to provide reasonable suggestions for the sustainable development of CIGS and the harmless disposal of spent CIGS.
2023, vol. 30, no. 6, pp.
1003-1024.
https://doi.org/10.1007/s12613-022-2595-0
Abstract:
With the rapid development of artificial intelligence technology and increasing material data, machine learning- and artificial intelligence-assisted design of high-performance steel materials is becoming a mainstream paradigm in materials science. Machine learning methods, based on an interdisciplinary discipline between computer science, statistics and material science, are good at discovering correlations between numerous data points. Compared with the traditional physical modeling method in material science, the main advantage of machine learning is that it overcomes the complex physical mechanisms of the material itself and provides a new perspective for the research and development of novel materials. This review starts with data preprocessing and the introduction of different machine learning models, including algorithm selection and model evaluation. Then, some successful cases of applying machine learning methods in the field of steel research are reviewed based on the main theme of optimizing composition, structure, processing, and performance. The application of machine learning methods to the performance-oriented inverse design of material composition and detection of steel defects is also reviewed. Finally, the applicability and limitations of machine learning in the material field are summarized, and future directions and prospects are discussed.
With the rapid development of artificial intelligence technology and increasing material data, machine learning- and artificial intelligence-assisted design of high-performance steel materials is becoming a mainstream paradigm in materials science. Machine learning methods, based on an interdisciplinary discipline between computer science, statistics and material science, are good at discovering correlations between numerous data points. Compared with the traditional physical modeling method in material science, the main advantage of machine learning is that it overcomes the complex physical mechanisms of the material itself and provides a new perspective for the research and development of novel materials. This review starts with data preprocessing and the introduction of different machine learning models, including algorithm selection and model evaluation. Then, some successful cases of applying machine learning methods in the field of steel research are reviewed based on the main theme of optimizing composition, structure, processing, and performance. The application of machine learning methods to the performance-oriented inverse design of material composition and detection of steel defects is also reviewed. Finally, the applicability and limitations of machine learning in the material field are summarized, and future directions and prospects are discussed.
2023, vol. 30, no. 6, pp.
1025-1037.
https://doi.org/10.1007/s12613-022-2575-4
Abstract:
To solve the uneven burden of same-type holes reducing the blasting efficiency due to the limitation of drilling equipment, we need a double-face program-controlled planning method for hole position parameters used on a computer-controlled drilling jumbo. The cross-section splits into even and uneven areas. It also considers the uneven burden at the hole’s entrance and bottom. In the uneven area, various qualifying factors are made to optimize the hole spacing and maximize the burden uniformity, combined with the features of the area edges and grid-based segmentation methods. The hole position coordinates and angles in the even area are derived using recursion and iteration algorithms. As a case, this method presents all holes in a 4.8 m wide and 3.6 m high cross-section. Compared with the design produced by the drawing method, our planning in the uneven area improved the standard deviation of the hole burden by 40%. The improved hole layout facilitates the evolution of precise, efficient, and intelligent blasting in underground mines.
To solve the uneven burden of same-type holes reducing the blasting efficiency due to the limitation of drilling equipment, we need a double-face program-controlled planning method for hole position parameters used on a computer-controlled drilling jumbo. The cross-section splits into even and uneven areas. It also considers the uneven burden at the hole’s entrance and bottom. In the uneven area, various qualifying factors are made to optimize the hole spacing and maximize the burden uniformity, combined with the features of the area edges and grid-based segmentation methods. The hole position coordinates and angles in the even area are derived using recursion and iteration algorithms. As a case, this method presents all holes in a 4.8 m wide and 3.6 m high cross-section. Compared with the design produced by the drawing method, our planning in the uneven area improved the standard deviation of the hole burden by 40%. The improved hole layout facilitates the evolution of precise, efficient, and intelligent blasting in underground mines.
2023, vol. 30, no. 6, pp.
1038-1047.
https://doi.org/10.1007/s12613-022-2580-7
Abstract:
We analyzed a novel cationic collector using chemical plant byproducts, such as cetyltrimethylammonium bromide (CTAB) and dibutyl phthalate (DBP). Our aim is to establish a highly effective and economical process for the removal of quartz from collophane. A microflotation test with a 25 mg·L−1 collector at pH value of 6–10 demonstrates a considerable difference in the floatability of pure quartz and fluorapatite. Flotation tests for a collophane sample subjected to the first reverse flotation for magnesium removal demonstrates that a rough flotation process (using a 0.4 kg·t−1 new collector at pH = 6) results in a collophane concentrate with 29.33wt% P2O5 grade and 12.66wt% SiO2 at a 79.69wt% P2O5 recovery, providing desirable results. Mechanism studies using Fourier transform infrared spectroscopy, zeta potential, and contact angle measurements show that the adsorption capacity of the new collector for quartz is higher than that for fluorapatite. The synergistic effect of DBP increases the difference in hydrophobicity between quartz and fluorapatite. The maximum defoaming rate of the novel cationic collector reaches 142.8 mL·min−1. This is considerably higher than that of a conventional cationic collector.
We analyzed a novel cationic collector using chemical plant byproducts, such as cetyltrimethylammonium bromide (CTAB) and dibutyl phthalate (DBP). Our aim is to establish a highly effective and economical process for the removal of quartz from collophane. A microflotation test with a 25 mg·L−1 collector at pH value of 6–10 demonstrates a considerable difference in the floatability of pure quartz and fluorapatite. Flotation tests for a collophane sample subjected to the first reverse flotation for magnesium removal demonstrates that a rough flotation process (using a 0.4 kg·t−1 new collector at pH = 6) results in a collophane concentrate with 29.33wt% P2O5 grade and 12.66wt% SiO2 at a 79.69wt% P2O5 recovery, providing desirable results. Mechanism studies using Fourier transform infrared spectroscopy, zeta potential, and contact angle measurements show that the adsorption capacity of the new collector for quartz is higher than that for fluorapatite. The synergistic effect of DBP increases the difference in hydrophobicity between quartz and fluorapatite. The maximum defoaming rate of the novel cationic collector reaches 142.8 mL·min−1. This is considerably higher than that of a conventional cationic collector.
2023, vol. 30, no. 6, pp.
1048-1056.
https://doi.org/10.1007/s12613-022-2586-1
Abstract:
This study synthesised a zincic salt (ZS) as a depressant for marmatite–galena separation. The effect of ZS on the flotation of marmatite and galena was investigated through micro-flotation tests. 88.89% of the galena was recovered and 83.39% of the marmatite was depressed with ZS dosage of 750 mg·L−1 at pH = 4. The depression mechanism of ZS on marmatite was investigated by a variety of techniques, including adsorption measurements, Fourier transform infrared (FTIR), X-ray photoelectron spectroscopic (XPS) analysis, and time of flight secondary ion mass spectrometry (ToF-SIMS). Results of adsorption tests and FTIR reveal that ZS adsorbed on marmatite surface and impeded the subsequent adsorption of butyl xanthate (BX). The results of XPS and ToF-SIMS indicate that the\begin{document}$ {\mathrm{Z}\mathrm{n}\mathrm{O}}_{2}^{2-} $\end{document} ![]()
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This study synthesised a zincic salt (ZS) as a depressant for marmatite–galena separation. The effect of ZS on the flotation of marmatite and galena was investigated through micro-flotation tests. 88.89% of the galena was recovered and 83.39% of the marmatite was depressed with ZS dosage of 750 mg·L−1 at pH = 4. The depression mechanism of ZS on marmatite was investigated by a variety of techniques, including adsorption measurements, Fourier transform infrared (FTIR), X-ray photoelectron spectroscopic (XPS) analysis, and time of flight secondary ion mass spectrometry (ToF-SIMS). Results of adsorption tests and FTIR reveal that ZS adsorbed on marmatite surface and impeded the subsequent adsorption of butyl xanthate (BX). The results of XPS and ToF-SIMS indicate that the
2023, vol. 30, no. 6, pp.
1057-1066.
https://doi.org/10.1007/s12613-022-2576-3
Abstract:
Magnetization roasting is one of the most effective way of utilizing low-grade refractory iron ore. However, the reduction roasting of siderite (FeCO3) generates weakly magnetic wüstite, thus reducing iron recovery via weak magnetic separation. We systematically studied and proposed the fluidized preoxidation–low-temperature reduction magnetization roasting process for siderite. We found that the maghemite generated during the air oxidation roasting of siderite would be further reduced into wüstite at 500 and 550°C due to the unstable intermediate product magnetite (Fe3O4). Stable magnetite can be obtained through maghemite reduction only at low temperature. The optimal fluidized magnetization roasting parameters included preoxidation at 610°C for 2.5 min, followed by reduction at 450°C for 5 min. For roasted ore, weak magnetic separation yielded an iron ore concentrate grade of 62.0wt% and an iron recovery rate of 88.36%. Compared with that of conventional direct reduction magnetization roasting, the iron recovery rate of weak magnetic separation had greatly improved by 34.33%. The proposed fluidized preoxidation–low-temperature reduction magnetization roasting process can realize the efficient magnetization roasting utilization of low-grade refractory siderite-containing iron ore without wüstite generation and is unlimited by the proportion of siderite and hematite in iron ore.
Magnetization roasting is one of the most effective way of utilizing low-grade refractory iron ore. However, the reduction roasting of siderite (FeCO3) generates weakly magnetic wüstite, thus reducing iron recovery via weak magnetic separation. We systematically studied and proposed the fluidized preoxidation–low-temperature reduction magnetization roasting process for siderite. We found that the maghemite generated during the air oxidation roasting of siderite would be further reduced into wüstite at 500 and 550°C due to the unstable intermediate product magnetite (Fe3O4). Stable magnetite can be obtained through maghemite reduction only at low temperature. The optimal fluidized magnetization roasting parameters included preoxidation at 610°C for 2.5 min, followed by reduction at 450°C for 5 min. For roasted ore, weak magnetic separation yielded an iron ore concentrate grade of 62.0wt% and an iron recovery rate of 88.36%. Compared with that of conventional direct reduction magnetization roasting, the iron recovery rate of weak magnetic separation had greatly improved by 34.33%. The proposed fluidized preoxidation–low-temperature reduction magnetization roasting process can realize the efficient magnetization roasting utilization of low-grade refractory siderite-containing iron ore without wüstite generation and is unlimited by the proportion of siderite and hematite in iron ore.
2023, vol. 30, no. 6, pp.
1067-1077.
https://doi.org/10.1007/s12613-022-2585-2
Abstract:
To assess the widely used submerged side-blowing in pyrometallurgy, a high-speed camera–digital image processing–statistical approach was used to systematically investigate the effects of the gas flow rate, nozzle diameter, and inclination angle on the space–time distribution and penetration behavior of submerged side-blown gas in an air–water system. The results show that the gas motion gradually changes from a bubbling regime to a steady jetting regime and the formation of a complete jet structure as the flow rate increases. When the flow rate is low, a bubble area is formed by large bubbles in the area above the nozzle. When the flow rate and the nozzle diameter are significant, a bubble area is formed by tiny bubbles in the area above the nozzle. The increased inclination angle requires a more significant flow rate to form a complete jet structure. In the sampling time, the dimensionless horizontal and vertical penetration depths are Gaussian distributed. Decreasing the nozzle diameter and increasing the flow rate or inclination angle will increase the distribution range and discreteness. New correlations for a penetration depth with an error of ±20% were obtained through dimensional analysis. The dimensionless horizontal penetration depth of an argon-melt system in a 120 t converter calculated by the correlation proposed by the current study is close to the result calculated by a correlation in the literature and a numerical simulation result in the literature.
To assess the widely used submerged side-blowing in pyrometallurgy, a high-speed camera–digital image processing–statistical approach was used to systematically investigate the effects of the gas flow rate, nozzle diameter, and inclination angle on the space–time distribution and penetration behavior of submerged side-blown gas in an air–water system. The results show that the gas motion gradually changes from a bubbling regime to a steady jetting regime and the formation of a complete jet structure as the flow rate increases. When the flow rate is low, a bubble area is formed by large bubbles in the area above the nozzle. When the flow rate and the nozzle diameter are significant, a bubble area is formed by tiny bubbles in the area above the nozzle. The increased inclination angle requires a more significant flow rate to form a complete jet structure. In the sampling time, the dimensionless horizontal and vertical penetration depths are Gaussian distributed. Decreasing the nozzle diameter and increasing the flow rate or inclination angle will increase the distribution range and discreteness. New correlations for a penetration depth with an error of ±20% were obtained through dimensional analysis. The dimensionless horizontal penetration depth of an argon-melt system in a 120 t converter calculated by the correlation proposed by the current study is close to the result calculated by a correlation in the literature and a numerical simulation result in the literature.
2023, vol. 30, no. 6, pp.
1078-1092.
https://doi.org/10.1007/s12613-022-2584-3
Abstract:
Pure Ni and its composites with different percentages of Ni–Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior. A nano-oxide composite of Ni–Cr was first synthesized through chemical coprecipitation with uniform distribution constituents. Electrodeposition was employed to coat pure Ni and Ni–(Ni–Cr) oxides (10, 20, 30, 40, and 50 g/L) on the steel sheets. Transmission electron microscope and field emission scanning electron microscope were adopted to examine the microstructure of powders and coatings, and X-ray diffraction analysis was employed to study the chemical composition. The microhardness, thickness, and wear resistance of the coatings were assessed, polarization and electrochemical impedance spectroscopy (EIS) tests were conducted to analyze the corrosion behavior, and the corresponding equivalent circuit was developed. Results showed flawless and crack-free coatings for all samples and uniform distribution of nano-oxides in the Ni matrix for the samples of 10–30 g/L. Agglomerated oxides were detected at high concentrations. Maximum microhardness (HV 661), thickness (116 µm), and wear resistance of coatings were found at 30 g/L. A three-loop equivalent circuit corresponded satisfactorily to all EIS data. The corrosion resistance increased with the nano-oxide concentration of up to 30 g/L but decreased at 40 g/L. The sample of 50 g/L showed the best corrosion resistance.
Pure Ni and its composites with different percentages of Ni–Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior. A nano-oxide composite of Ni–Cr was first synthesized through chemical coprecipitation with uniform distribution constituents. Electrodeposition was employed to coat pure Ni and Ni–(Ni–Cr) oxides (10, 20, 30, 40, and 50 g/L) on the steel sheets. Transmission electron microscope and field emission scanning electron microscope were adopted to examine the microstructure of powders and coatings, and X-ray diffraction analysis was employed to study the chemical composition. The microhardness, thickness, and wear resistance of the coatings were assessed, polarization and electrochemical impedance spectroscopy (EIS) tests were conducted to analyze the corrosion behavior, and the corresponding equivalent circuit was developed. Results showed flawless and crack-free coatings for all samples and uniform distribution of nano-oxides in the Ni matrix for the samples of 10–30 g/L. Agglomerated oxides were detected at high concentrations. Maximum microhardness (HV 661), thickness (116 µm), and wear resistance of coatings were found at 30 g/L. A three-loop equivalent circuit corresponded satisfactorily to all EIS data. The corrosion resistance increased with the nano-oxide concentration of up to 30 g/L but decreased at 40 g/L. The sample of 50 g/L showed the best corrosion resistance.
2023, vol. 30, no. 6, pp.
1093-1103.
https://doi.org/10.1007/s12613-022-2536-y
Abstract:
Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production. It has been difficult to meet the needs of the field with the usual prediction model of mechanical properties of hot-rolled strip. Insufficient data and difficult parameter adjustment limit deep learning models based on multi-layer networks in practical applications; besides, the limited discrete process parameters used make it impossible to effectively depict the actual strip processing process. In order to solve these problems, this research proposed a new sampling approach for mechanical characteristics input data of hot-rolled strip based on the multi-grained cascade forest (gcForest) framework. According to the characteristics of complex process flow and abnormal sensitivity of process path and parameters to product quality in the hot-rolled strip production, a three-dimensional continuous time series process data sampling method based on time–temperature–deformation was designed. The basic information of strip steel (chemical composition and typical process parameters) is fused with the local process information collected by multi-grained scanning, so that the next link’s input has both local and global features. Furthermore, in the multi-grained scanning structure, a sub sampling scheme with a variable window was designed, so that input data with different dimensions can get output characteristics of the same dimension after passing through the multi-grained scanning structure, allowing the cascade forest structure to be trained normally. Finally, actual production data of three steel grades was used to conduct the experimental evaluation. The results revealed that the gcForest-based mechanical property prediction model outperforms the competition in terms of comprehensive performance, ease of parameter adjustment, and ability to sustain high prediction accuracy with fewer samples.
Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production. It has been difficult to meet the needs of the field with the usual prediction model of mechanical properties of hot-rolled strip. Insufficient data and difficult parameter adjustment limit deep learning models based on multi-layer networks in practical applications; besides, the limited discrete process parameters used make it impossible to effectively depict the actual strip processing process. In order to solve these problems, this research proposed a new sampling approach for mechanical characteristics input data of hot-rolled strip based on the multi-grained cascade forest (gcForest) framework. According to the characteristics of complex process flow and abnormal sensitivity of process path and parameters to product quality in the hot-rolled strip production, a three-dimensional continuous time series process data sampling method based on time–temperature–deformation was designed. The basic information of strip steel (chemical composition and typical process parameters) is fused with the local process information collected by multi-grained scanning, so that the next link’s input has both local and global features. Furthermore, in the multi-grained scanning structure, a sub sampling scheme with a variable window was designed, so that input data with different dimensions can get output characteristics of the same dimension after passing through the multi-grained scanning structure, allowing the cascade forest structure to be trained normally. Finally, actual production data of three steel grades was used to conduct the experimental evaluation. The results revealed that the gcForest-based mechanical property prediction model outperforms the competition in terms of comprehensive performance, ease of parameter adjustment, and ability to sustain high prediction accuracy with fewer samples.
2023, vol. 30, no. 6, pp.
1104-1112.
https://doi.org/10.1007/s12613-023-2603-z
Abstract:
Mg–3Al–1Zn (AZ31) sheets were produced by transverse gradient extrusion (TGE) process. The flow behavior and dynamic recrystallization during extrusion were systematically analyzed. The microstructures, textures, and mechanical behavior of extruded AZ31 sheet were also analyzed and compared with conventional extruded (CE) sheet. The results showed that fine grain structure and multi-type unique textures were formed in TGE sheet because of the generation of extra flow velocity along transverse direction (TD) and flow velocity gradient along extrusion direction (ED) during extrusion. The basal poles gradually deviated away normal direction (ND) from edge to center of the TGE sheet along TD, and the largest inclination angle at center region reached around 65°. Furthermore, the basal poles inclined from ED to TD 40°–63°, except for the center region of TGE sheet. The TGE sheet presented higher ductility and strain hardening exponent (n-value), but lower yield strength and Lankford value (r-value) in comparison with the CE sheet. Both the basal <a> slip and tensile twins were easy to be activated during deformation, and the largest elongation of 41% and the lowest yield strength of 86.5 MPa were obtained for the ED-center sample in the TGE sheet.
Mg–3Al–1Zn (AZ31) sheets were produced by transverse gradient extrusion (TGE) process. The flow behavior and dynamic recrystallization during extrusion were systematically analyzed. The microstructures, textures, and mechanical behavior of extruded AZ31 sheet were also analyzed and compared with conventional extruded (CE) sheet. The results showed that fine grain structure and multi-type unique textures were formed in TGE sheet because of the generation of extra flow velocity along transverse direction (TD) and flow velocity gradient along extrusion direction (ED) during extrusion. The basal poles gradually deviated away normal direction (ND) from edge to center of the TGE sheet along TD, and the largest inclination angle at center region reached around 65°. Furthermore, the basal poles inclined from ED to TD 40°–63°, except for the center region of TGE sheet. The TGE sheet presented higher ductility and strain hardening exponent (n-value), but lower yield strength and Lankford value (r-value) in comparison with the CE sheet. Both the basal <a> slip and tensile twins were easy to be activated during deformation, and the largest elongation of 41% and the lowest yield strength of 86.5 MPa were obtained for the ED-center sample in the TGE sheet.
2023, vol. 30, no. 6, pp.
1113-1127.
https://doi.org/10.1007/s12613-022-2581-6
Abstract:
To protect the AM60B magnesium alloy from corrosion, a sol–gel coating containing hydroxylated g-C3N4 nanoplates was applied. The chemical composition of the hydroxylated g-C3N4 nanoplates was investigated using X-ray photoelectron spectroscopy (XPS). The hydroxylation process did not affect the crystal size, specific surface area, pore volume, average pore diameter, and thermal stability of the g-C3N4 nanoplates. After incorporating pristine and hydroxylated g-C3N4 nanoplates, dense sol–gel coatings were obtained. Transmission electron microscopy (TEM) revealed the uniform distribution of the modified g-C3N4 in the coating. The average roughness of the coating was also reduced after adding the modified nanoplates due to the decreased aggregation tendency. Electrochemical impedance spectroscopy (EIS) examinations in simulated acid rain revealed a significant improvement in the anticorrosion properties of the sol–gel film after the addition of the modified g-C3N4 due to the chemical bonding of the coating to the nanoplates.
To protect the AM60B magnesium alloy from corrosion, a sol–gel coating containing hydroxylated g-C3N4 nanoplates was applied. The chemical composition of the hydroxylated g-C3N4 nanoplates was investigated using X-ray photoelectron spectroscopy (XPS). The hydroxylation process did not affect the crystal size, specific surface area, pore volume, average pore diameter, and thermal stability of the g-C3N4 nanoplates. After incorporating pristine and hydroxylated g-C3N4 nanoplates, dense sol–gel coatings were obtained. Transmission electron microscopy (TEM) revealed the uniform distribution of the modified g-C3N4 in the coating. The average roughness of the coating was also reduced after adding the modified nanoplates due to the decreased aggregation tendency. Electrochemical impedance spectroscopy (EIS) examinations in simulated acid rain revealed a significant improvement in the anticorrosion properties of the sol–gel film after the addition of the modified g-C3N4 due to the chemical bonding of the coating to the nanoplates.
2023, vol. 30, no. 6, pp.
1128-1139.
https://doi.org/10.1007/s12613-023-2596-7
Abstract:
Magnesium (Mg) alloys, the lightest metal construction material used in industry, play a vital role in future development. However, the poor corrosion resistance of Mg alloys in corrosion environments largely limits their potential wide applications. Therefore, a micro-arc oxidation/graphene oxide/stearic acid (MAO/GO/SA) superhydrophobic composite coating with superior corrosion resistance was fabricated on a Mg alloy AZ91D through micro-arc oxidation (MAO) technology, electrodeposition technique, and self-assembly technology. The composition and microstructure of the coating were characterized by scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Raman spectroscopy. The effective protection of the MAO/GO/SA composite coating applied to a substrate was evaluated using potentiodynamic polarization, electrochemical impedance spectroscopy tests, and salt spray tests. The results showed that the MAO/GO/SA composite coating with a petal spherical structure had the best superhydrophobicity, and it attained a contact angle of 159.53° ± 2°. The MAO/GO/SA composite coating exhibited high resistance to corrosion, according to electrochemical and salt spray tests.
Magnesium (Mg) alloys, the lightest metal construction material used in industry, play a vital role in future development. However, the poor corrosion resistance of Mg alloys in corrosion environments largely limits their potential wide applications. Therefore, a micro-arc oxidation/graphene oxide/stearic acid (MAO/GO/SA) superhydrophobic composite coating with superior corrosion resistance was fabricated on a Mg alloy AZ91D through micro-arc oxidation (MAO) technology, electrodeposition technique, and self-assembly technology. The composition and microstructure of the coating were characterized by scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Raman spectroscopy. The effective protection of the MAO/GO/SA composite coating applied to a substrate was evaluated using potentiodynamic polarization, electrochemical impedance spectroscopy tests, and salt spray tests. The results showed that the MAO/GO/SA composite coating with a petal spherical structure had the best superhydrophobicity, and it attained a contact angle of 159.53° ± 2°. The MAO/GO/SA composite coating exhibited high resistance to corrosion, according to electrochemical and salt spray tests.
2023, vol. 30, no. 6, pp.
1140-1151.
https://doi.org/10.1007/s12613-022-2592-3
Abstract:
The introduction of in-pipe robots for sewage cleaning provides researchers with new options for pipe inspection, such as leakage, crack, gas, and corrosion detection, which are standard applications common in the current industrial scenario. The question that is frequently overlooked in all these cases is the inherent resistance of the robots to corrosion. The mechanical, microstructural, and corrosion properties of aluminum 7075 incorporated with various weight percentages (0, 0.5wt%, 1wt%, and 1.5wt%) of carbon nanotubes (CNTs) are discussed. It is fabricated using a rotational ultrasonication with mechanical stirring (RUMS)-based casting method for improved corrosion resistance without compromising the mechanical properties of the robot. 1wt% CNTs–aluminum nanocomposite shows good corrosion and mechanical properties, meeting the requirements imposed by the sewage environment of the robot.
The introduction of in-pipe robots for sewage cleaning provides researchers with new options for pipe inspection, such as leakage, crack, gas, and corrosion detection, which are standard applications common in the current industrial scenario. The question that is frequently overlooked in all these cases is the inherent resistance of the robots to corrosion. The mechanical, microstructural, and corrosion properties of aluminum 7075 incorporated with various weight percentages (0, 0.5wt%, 1wt%, and 1.5wt%) of carbon nanotubes (CNTs) are discussed. It is fabricated using a rotational ultrasonication with mechanical stirring (RUMS)-based casting method for improved corrosion resistance without compromising the mechanical properties of the robot. 1wt% CNTs–aluminum nanocomposite shows good corrosion and mechanical properties, meeting the requirements imposed by the sewage environment of the robot.
2023, vol. 30, no. 6, pp.
1152-1161.
https://doi.org/10.1007/s12613-022-2590-5
Abstract:
Because of their large volume variation and inferior electrical conductivity, Mn3O4-based oxide anode materials have short cyclic lives and poor rate capability, which obstructs their development. In this study, we successfully prepared a Mn3O4/N-doped honeycomb carbon composite using a smart and facile synthetic method. The Mn3O4 nanopolyhedra are grown on N-doped honeycomb carbon, which evidently mitigates the volume change in the charging and discharging processes but also improves the electrochemical reaction kinetics. More importantly, the Mn–O–C bond in the Mn3O4/N-doped honeycomb carbon composite benefits electrochemical reversibility. These features of the Mn3O4/N-doped honeycomb carbon (NHC) composite are responsible for its superior electrochemical performance. When used for Li-ion batteries, the Mn3O4/N-doped honeycomb carbon anode exhibits a high reversible capacity of 598 mAh·g−1 after 350 cycles at 1 A·g−1. Even at 2 A·g−1, the Mn3O4/NHC anode still delivers a high capacity of 472 mAh·g−1. This work provides a new prospect for synthesizing and developing manganese-based oxide materials for energy storage.
Because of their large volume variation and inferior electrical conductivity, Mn3O4-based oxide anode materials have short cyclic lives and poor rate capability, which obstructs their development. In this study, we successfully prepared a Mn3O4/N-doped honeycomb carbon composite using a smart and facile synthetic method. The Mn3O4 nanopolyhedra are grown on N-doped honeycomb carbon, which evidently mitigates the volume change in the charging and discharging processes but also improves the electrochemical reaction kinetics. More importantly, the Mn–O–C bond in the Mn3O4/N-doped honeycomb carbon composite benefits electrochemical reversibility. These features of the Mn3O4/N-doped honeycomb carbon (NHC) composite are responsible for its superior electrochemical performance. When used for Li-ion batteries, the Mn3O4/N-doped honeycomb carbon anode exhibits a high reversible capacity of 598 mAh·g−1 after 350 cycles at 1 A·g−1. Even at 2 A·g−1, the Mn3O4/NHC anode still delivers a high capacity of 472 mAh·g−1. This work provides a new prospect for synthesizing and developing manganese-based oxide materials for energy storage.
2023, vol. 30, no. 6, pp.
1162-1170.
https://doi.org/10.1007/s12613-022-2577-2
Abstract:
With the number of decommissioned electric vehicles increasing annually, a large amount of discarded power battery cathode material is in urgent need of treatment. However, common leaching methods for recovering metal salts are economically inefficient and polluting. Meanwhile, the recycled material obtained by lithium remediation alone has limited performance in cycling stability. Herein, a short method of solid-phase reduction is developed to recover spent LiFePO4 by simultaneously introducing Mg2+ ions for hetero-atom doping. Issues of particle agglomeration, carbon layer breakage, lithium loss, and Fe3+ defects in spent LiFePO4 are also addressed. Results show that Mg2+ addition during regeneration can remarkably enhance the crystal structure stability and improve the Li+ diffusion coefficient. The regenerated LiFePO4 exhibits significantly improved electrochemical performance with a specific discharge capacity of 143.2 mAh·g−1 at 0.2 C, and its capacity retention is extremely increased from 37.9% to 98.5% over 200 cycles at 1 C. Especially, its discharge capacity can reach 95.5 mAh·g−1 at 10 C, which is higher than that of spent LiFePO4 (55.9 mAh·g−1). All these results show that the proposed regeneration strategy of simultaneous carbon coating and Mg2+ doping is suitable for the efficient treatment of spent LiFePO4.
With the number of decommissioned electric vehicles increasing annually, a large amount of discarded power battery cathode material is in urgent need of treatment. However, common leaching methods for recovering metal salts are economically inefficient and polluting. Meanwhile, the recycled material obtained by lithium remediation alone has limited performance in cycling stability. Herein, a short method of solid-phase reduction is developed to recover spent LiFePO4 by simultaneously introducing Mg2+ ions for hetero-atom doping. Issues of particle agglomeration, carbon layer breakage, lithium loss, and Fe3+ defects in spent LiFePO4 are also addressed. Results show that Mg2+ addition during regeneration can remarkably enhance the crystal structure stability and improve the Li+ diffusion coefficient. The regenerated LiFePO4 exhibits significantly improved electrochemical performance with a specific discharge capacity of 143.2 mAh·g−1 at 0.2 C, and its capacity retention is extremely increased from 37.9% to 98.5% over 200 cycles at 1 C. Especially, its discharge capacity can reach 95.5 mAh·g−1 at 10 C, which is higher than that of spent LiFePO4 (55.9 mAh·g−1). All these results show that the proposed regeneration strategy of simultaneous carbon coating and Mg2+ doping is suitable for the efficient treatment of spent LiFePO4.
2023, vol. 30, no. 6, pp.
1171-1180.
https://doi.org/10.1007/s12613-022-2591-4
Abstract:
Tin-based materials are very attractive anodes because of their high theoretical capacity, but their rapid capacity fading from volume expansions limits their practical applications during alloying and dealloying processes. Herein, the improved binder-free tin-copper intermetallic/carbon nanotubes (Cu6Sn5/CNTs) alloy thin-film electrodes are directly fabricated through efficient in situ electrodeposition from the leaching solution of treated waste-printed circuit boards (WPCBs). The characterization results show that the easily agglomerated Cu6Sn5 alloy nanoparticles are uniformly dispersed across the three-dimensional network when the CNTs concentration in the electrodeposition solution is maintained at 0.2 g·L−1. Moreover, the optimal Cu6Sn5/CNTs-0.2 alloy thin-film electrode can not only provide a decent discharge specific capacity of 458.35 mAh·g−1 after 50 cycles at 100 mA·g−1 within capacity retention of 82.58% but also deliver a relatively high reversible specific capacity of 518.24, 445.52, 418.18, 345.33, and 278.05 mAh·g−1 at step-increased current density of 0.1, 0.2, 0.5, 1.0, and 2.0 A·g−1, respectively. Therefore, the preparation process of the Cu6Sn5/CNTs-0.2 alloy thin-film electrode with improved electrochemical performance may provide a cost-effective strategy for the resource utilization of WPCBs to fabricate anode materials for lithium-ion batteries.
Tin-based materials are very attractive anodes because of their high theoretical capacity, but their rapid capacity fading from volume expansions limits their practical applications during alloying and dealloying processes. Herein, the improved binder-free tin-copper intermetallic/carbon nanotubes (Cu6Sn5/CNTs) alloy thin-film electrodes are directly fabricated through efficient in situ electrodeposition from the leaching solution of treated waste-printed circuit boards (WPCBs). The characterization results show that the easily agglomerated Cu6Sn5 alloy nanoparticles are uniformly dispersed across the three-dimensional network when the CNTs concentration in the electrodeposition solution is maintained at 0.2 g·L−1. Moreover, the optimal Cu6Sn5/CNTs-0.2 alloy thin-film electrode can not only provide a decent discharge specific capacity of 458.35 mAh·g−1 after 50 cycles at 100 mA·g−1 within capacity retention of 82.58% but also deliver a relatively high reversible specific capacity of 518.24, 445.52, 418.18, 345.33, and 278.05 mAh·g−1 at step-increased current density of 0.1, 0.2, 0.5, 1.0, and 2.0 A·g−1, respectively. Therefore, the preparation process of the Cu6Sn5/CNTs-0.2 alloy thin-film electrode with improved electrochemical performance may provide a cost-effective strategy for the resource utilization of WPCBs to fabricate anode materials for lithium-ion batteries.
2023, vol. 30, no. 6, pp.
1181-1189.
https://doi.org/10.1007/s12613-023-2616-7
Abstract:
Performance degradation shortens the life of solid oxide fuel cells in practical applications. Revealing the degradation mechanism is crucial for the continuous improvement of cell durability. In this work, the effects of cell operating conditions on the terminal voltage and anode microstructure of a Ni–yttria-stabilized zirconia anode-supported single cell were investigated. The microstructure of the anode active area near the electrolyte was characterized by laser optical microscopy and focused ion beam-scanning electron microscopy. Ni depletion at the anode/electrolyte interface region was observed after 100 h discharge tests. In addition, the long-term stability of the single cell was evaluated at 700°C for 3000 h. After an initial decline, the anode-supported single cell exhibits good durability with a voltage decay rate of 0.72%/kh and an electrode polarization resistance decay rate of 0.17%/kh. The main performance loss of the cell originates from the initial degradation.
Performance degradation shortens the life of solid oxide fuel cells in practical applications. Revealing the degradation mechanism is crucial for the continuous improvement of cell durability. In this work, the effects of cell operating conditions on the terminal voltage and anode microstructure of a Ni–yttria-stabilized zirconia anode-supported single cell were investigated. The microstructure of the anode active area near the electrolyte was characterized by laser optical microscopy and focused ion beam-scanning electron microscopy. Ni depletion at the anode/electrolyte interface region was observed after 100 h discharge tests. In addition, the long-term stability of the single cell was evaluated at 700°C for 3000 h. After an initial decline, the anode-supported single cell exhibits good durability with a voltage decay rate of 0.72%/kh and an electrode polarization resistance decay rate of 0.17%/kh. The main performance loss of the cell originates from the initial degradation.
2023, vol. 30, no. 6, pp.
1190-1197.
https://doi.org/10.1007/s12613-023-2620-y
Abstract:
Physical vapor deposition (PVD) can be used to produce high-quality Gd2O3-doped CeO2 (GDC) films. Among various PVD methods, reactive sputtering provides unique benefits, such as high deposition rates and easy upscaling for industrial applications. GDC thin films were successfully fabricated through reactive sputtering using a Gd0.2Ce0.8 (at%) metallic target, and their application in solid oxide fuel cells, such as buffer layers between yttria-stabilized zirconia (YSZ)/La0.6Sr0.4Co0.2Fe0.8O3−δ and as sublayers in the steel/coating system, was evaluated. First, the direct current (DC) reactive-sputtering behavior of the GdCe metallic target was determined. Then, the GDC films were deposited on NiO–YSZ/YSZ half-cells to investigate the influence of oxygen flow rate on the quality of annealed GDC films. The results demonstrated that reactive sputtering can be used to prepare thin and dense GDC buffer layers without high-temperature sintering. Furthermore, the cells with a sputtered GDC buffer layer showed better electrochemical performance than those with a screen-printed GDC buffer layer. In addition, the insertion of a GDC sublayer between the SUS441 interconnects and the Mn–Co spinel coatings contributed to the reduction of the oxidation rate for SUS441 at operating temperatures, according to the area-specific resistance tests.
Physical vapor deposition (PVD) can be used to produce high-quality Gd2O3-doped CeO2 (GDC) films. Among various PVD methods, reactive sputtering provides unique benefits, such as high deposition rates and easy upscaling for industrial applications. GDC thin films were successfully fabricated through reactive sputtering using a Gd0.2Ce0.8 (at%) metallic target, and their application in solid oxide fuel cells, such as buffer layers between yttria-stabilized zirconia (YSZ)/La0.6Sr0.4Co0.2Fe0.8O3−δ and as sublayers in the steel/coating system, was evaluated. First, the direct current (DC) reactive-sputtering behavior of the GdCe metallic target was determined. Then, the GDC films were deposited on NiO–YSZ/YSZ half-cells to investigate the influence of oxygen flow rate on the quality of annealed GDC films. The results demonstrated that reactive sputtering can be used to prepare thin and dense GDC buffer layers without high-temperature sintering. Furthermore, the cells with a sputtered GDC buffer layer showed better electrochemical performance than those with a screen-printed GDC buffer layer. In addition, the insertion of a GDC sublayer between the SUS441 interconnects and the Mn–Co spinel coatings contributed to the reduction of the oxidation rate for SUS441 at operating temperatures, according to the area-specific resistance tests.
2023, vol. 30, no. 6, pp.
1198-1206.
https://doi.org/10.1007/s12613-022-2583-4
Abstract:
The demand of high-end electromagnetic wave absorbing materials puts forward higher requirements on comprehensive performances of small thickness, lightweight, broadband, and strong absorption. Herein, a novel multi-layer stepped metamaterial absorber with gradient electromagnetic properties is proposed. The complex permittivity and permeability of each layer are tailored via the proportion of carbonyl-iron and carbon-fiber dispersing into the epoxy resin. The proposed metamaterial is further optimized via adjusting the electromagnetic parameters and geometric sizes of each layer. Comparing with the four-layer composite with gradient electromagnetic properties which could only realize reflection loss (RL) of less than −6 dB in 2.0–40 GHz, the optimized stepped metamaterial with the same thickness and electromagnetic properties realizes less than −10 dB in the relevant frequency range. Additionally, the RL of less than −15 dB is achieved in the frequency range of 11.2–21.4 GHz and 28.5–40 GHz. The multiple electromagnetic wave absorption mechanism is discussed based on the experimental and simulation results, which is believed to be attributed to the synergy effect induced by multi-scale structures of the metamaterial. Therefore, combining multi-layer structures and periodic stepped structures into a novel gradient absorbing metamaterial would give new insights into designing microwave absorption devices for broadband electromagnetic protections.
The demand of high-end electromagnetic wave absorbing materials puts forward higher requirements on comprehensive performances of small thickness, lightweight, broadband, and strong absorption. Herein, a novel multi-layer stepped metamaterial absorber with gradient electromagnetic properties is proposed. The complex permittivity and permeability of each layer are tailored via the proportion of carbonyl-iron and carbon-fiber dispersing into the epoxy resin. The proposed metamaterial is further optimized via adjusting the electromagnetic parameters and geometric sizes of each layer. Comparing with the four-layer composite with gradient electromagnetic properties which could only realize reflection loss (RL) of less than −6 dB in 2.0–40 GHz, the optimized stepped metamaterial with the same thickness and electromagnetic properties realizes less than −10 dB in the relevant frequency range. Additionally, the RL of less than −15 dB is achieved in the frequency range of 11.2–21.4 GHz and 28.5–40 GHz. The multiple electromagnetic wave absorption mechanism is discussed based on the experimental and simulation results, which is believed to be attributed to the synergy effect induced by multi-scale structures of the metamaterial. Therefore, combining multi-layer structures and periodic stepped structures into a novel gradient absorbing metamaterial would give new insights into designing microwave absorption devices for broadband electromagnetic protections.
2023, vol. 30, no. 6, pp.
1207-1216.
https://doi.org/10.1007/s12613-022-2489-1
Abstract:
Augite-based glass ceramics were synthesised using ZnO, FeO, and Fe2O3 as additives, and the spinel formation, matrix structure, crystallisation thermodynamics, and physicochemical properties were investigated. The results showed that oxides resulted in numerous preliminary spinels in the glass matrix. FeO, ZnO, and Fe2O3 influenced the formation of spinel, while FeO simplified the glass network. FeO and ZnO promoted bulk crystallisation of the parent glass. After adding oxides, the grains of augite phase were refined, and the relative quantities of augite crystal planes were also influenced. All samples displayed good mechanical properties and chemical stability. The 2wt% ZnO-doping sample displayed the maximum flexural strength (170.3 MPa). Chromium leaching amount values of all the samples were less than the national standard (1.5 mg/L), confirming the safety of the materials. In conclusion, an appropriate amount of zinc-containing raw material is beneficial for the preparation of augite-based glass ceramics.
Augite-based glass ceramics were synthesised using ZnO, FeO, and Fe2O3 as additives, and the spinel formation, matrix structure, crystallisation thermodynamics, and physicochemical properties were investigated. The results showed that oxides resulted in numerous preliminary spinels in the glass matrix. FeO, ZnO, and Fe2O3 influenced the formation of spinel, while FeO simplified the glass network. FeO and ZnO promoted bulk crystallisation of the parent glass. After adding oxides, the grains of augite phase were refined, and the relative quantities of augite crystal planes were also influenced. All samples displayed good mechanical properties and chemical stability. The 2wt% ZnO-doping sample displayed the maximum flexural strength (170.3 MPa). Chromium leaching amount values of all the samples were less than the national standard (1.5 mg/L), confirming the safety of the materials. In conclusion, an appropriate amount of zinc-containing raw material is beneficial for the preparation of augite-based glass ceramics.
2023, vol. 30, no. 6, pp.
1217-1224.
https://doi.org/10.1007/s12613-023-2600-2
Abstract:
Si-based optical position-sensitive detectors (PSDs) have stimulated the interest of researchers due to their wide range of practical applications. However, due to the rigidity and fragility of Si crystals, the applications of flexible PSDs have been limited. Therefore, we presented a flexible broadband PSD based on a WS2/Si heterostructure for the first time. A scalable sputtering method was used to deposit WS2 thin films onto the etched ultrathin crystalline Si surface. The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450–1350 nm, with a high position sensitivity of ~539.8 mV·mm−1 and a fast response of 2.3 μs, thanks to the strong light absorption, the built-in electrical field at the WS2/Si interface, and facilitated transport. Furthermore, mechanical-bending tests revealed that after 200 mechanical-bending cycles, the WS2/Si PSDs have excellent mechanical flexibility, stability, and durability, demonstrating the great potential in wearable PSDs with competitive performance.
Si-based optical position-sensitive detectors (PSDs) have stimulated the interest of researchers due to their wide range of practical applications. However, due to the rigidity and fragility of Si crystals, the applications of flexible PSDs have been limited. Therefore, we presented a flexible broadband PSD based on a WS2/Si heterostructure for the first time. A scalable sputtering method was used to deposit WS2 thin films onto the etched ultrathin crystalline Si surface. The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450–1350 nm, with a high position sensitivity of ~539.8 mV·mm−1 and a fast response of 2.3 μs, thanks to the strong light absorption, the built-in electrical field at the WS2/Si interface, and facilitated transport. Furthermore, mechanical-bending tests revealed that after 200 mechanical-bending cycles, the WS2/Si PSDs have excellent mechanical flexibility, stability, and durability, demonstrating the great potential in wearable PSDs with competitive performance.
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