Forming aluminum foam into the desired shape is essential for actual product application, but aluminum foam is difficult to form. In this investigation, we attempted to press-form aluminum foam immediately after foaming the precursor and employed a neural network to estimate the properties of the press-formed aluminum foam from X-ray CT images. It was found that it was possible to press-form the aluminum foam immediately after foaming while maintaining the pores. The resulting aluminum foam exhibited a similar compressive behavior to non-press-formed aluminum foam. In addition, it was found that a neural network model for the estimation of plateau stress from X-ray CT images of non-press-formed aluminum foam can be created by training on a dataset of X-ray CT images and plateau stress obtained from actual compression tests of aluminum foam. From X-ray CT images, it was also suggested that this neural network model can also be used to estimate the plateau stress of press-formed aluminum foam that retains pores. That is, it was suggested that the neural network model created utilizing X-ray CT images can be employed to estimate the properties of products even when they are press-formed into complex shapes and their properties are difficult to evaluate.
{"title":"Press-forming of aluminum foam and estimation of its mechanical properties from X-ray CT images using machine learning","authors":"Yoshihiko Hangai, Yuki Sakaguchi, Kenji Okada, Yuuki Tanaka","doi":"10.1016/j.matchar.2025.114781","DOIUrl":"10.1016/j.matchar.2025.114781","url":null,"abstract":"<div><div>Forming aluminum foam into the desired shape is essential for actual product application, but aluminum foam is difficult to form. In this investigation, we attempted to press-form aluminum foam immediately after foaming the precursor and employed a neural network to estimate the properties of the press-formed aluminum foam from X-ray CT images. It was found that it was possible to press-form the aluminum foam immediately after foaming while maintaining the pores. The resulting aluminum foam exhibited a similar compressive behavior to non-press-formed aluminum foam. In addition, it was found that a neural network model for the estimation of plateau stress from X-ray CT images of non-press-formed aluminum foam can be created by training on a dataset of X-ray CT images and plateau stress obtained from actual compression tests of aluminum foam. From X-ray CT images, it was also suggested that this neural network model can also be used to estimate the plateau stress of press-formed aluminum foam that retains pores. That is, it was suggested that the neural network model created utilizing X-ray CT images can be employed to estimate the properties of products even when they are press-formed into complex shapes and their properties are difficult to evaluate.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114781"},"PeriodicalIF":4.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-30DOI: 10.1016/j.matchar.2025.114796
Ke Chen, Jiao Luo
In this work, the evolution mechanisms of microstructure subjected to deformation and heat treatment were thoroughly investigated using scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) observations. During deformation, γ matrix transformed into 9R structure via gliding of a/6[11] partial and then transformed into twin structure via gliding of a/6[11] and a/6[11] partials. Besides, fast grain boundary migration rate was beneficial for the development of twin boundaries (TBs). However, severe interaction between pre-existed TBs and dislocations dominated by activation of (11)[011] slip system would cause deviation of rotation angle and shift of rotation axis, leading to decreasing TBs density. During heat treatment, stored-energy-driven boundary migration was weakened due to consumption of stored energy, and curvature-driven boundary migration became dominated at different regions, reducing the positive effects of boundary migration on TBs development. Based on the above analysis, a novel design of microstructure with gradient TBs density by controlling-strain deformation and gradient-temperature heat treatment was proposed. Due to gradient strain, TBs density increased from the low-strain (LS) region to the high-strain (HS) region induced by 9R structure transformation and boundary migration. Due to gradient temperature, TBs density decreased obviously in the low-strain and high-temperature (LS-HT) region under the effect of grains annexation, while it only decreased slightly in the high-strain and low-temperature (HS-LT) region due to the poorer grain boundary mobility. Then, tensile strength and fracture toughness tests were carried out to evaluate the performance of gradient microstructure. The results showed that the as-prepared microstructure improved tensile strength by 13.6% from the intermediate transition (IT) region to the HS-LT region and fracture toughness by 11.7% from the IT region to the LS-HT region. Finally, the influence of as-prepared gradient microstructure on mechanical properties was thoroughly discussed.
{"title":"Formation of twin-density gradient induced by 9R structure transformation and boundary migration to improve performance in GH4586 superalloy","authors":"Ke Chen, Jiao Luo","doi":"10.1016/j.matchar.2025.114796","DOIUrl":"10.1016/j.matchar.2025.114796","url":null,"abstract":"<div><div>In this work, the evolution mechanisms of microstructure subjected to deformation and heat treatment were thoroughly investigated using scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) observations. During deformation, γ matrix transformed into 9R structure via gliding of a/6[11<span><math><mover><mn>2</mn><mo>¯</mo></mover></math></span>] partial and then transformed into twin structure via gliding of a/6[11<span><math><mover><mn>2</mn><mo>¯</mo></mover></math></span>] and a/6[1<span><math><mover><mn>2</mn><mo>¯</mo></mover></math></span>1] partials. Besides, fast grain boundary migration rate was beneficial for the development of twin boundaries (TBs). However, severe interaction between pre-existed TBs and dislocations dominated by activation of (1<span><math><mover><mn>2</mn><mo>¯</mo></mover></math></span>1)[011] slip system would cause deviation of rotation angle and shift of rotation axis, leading to decreasing TBs density. During heat treatment, stored-energy-driven boundary migration was weakened due to consumption of stored energy, and curvature-driven boundary migration became dominated at different regions, reducing the positive effects of boundary migration on TBs development. Based on the above analysis, a novel design of microstructure with gradient TBs density by controlling-strain deformation and gradient-temperature heat treatment was proposed. Due to gradient strain, TBs density increased from the low-strain (LS) region to the high-strain (HS) region induced by 9R structure transformation and boundary migration. Due to gradient temperature, TBs density decreased obviously in the low-strain and high-temperature (LS-HT) region under the effect of grains annexation, while it only decreased slightly in the high-strain and low-temperature (HS-LT) region due to the poorer grain boundary mobility. Then, tensile strength and fracture toughness tests were carried out to evaluate the performance of gradient microstructure. The results showed that the as-prepared microstructure improved tensile strength by 13.6% from the intermediate transition (IT) region to the HS-LT region and fracture toughness by 11.7% from the IT region to the LS-HT region. Finally, the influence of as-prepared gradient microstructure on mechanical properties was thoroughly discussed.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114796"},"PeriodicalIF":4.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-30DOI: 10.1016/j.matchar.2025.114795
Hannes Fröck , Benjamin Milkereit , Jette Broer , Armin Springer , Sigurd Wenner , Kevin Oldenburg , Tobias Kruse , Christian Kloetzer-Freese , Olaf Kessler
The CuAl bronze alloy CuAl10Ni5Fe5 has been widely used in maritime components, such as large ship propellers, for many decades because of its excellent corrosion resistance and mechanical properties. The alloy is mainly manufactured by casting. In the present work, its micro- and nanostructural development during cooling from solution treatments is investigated. The cooling rates were varied over four orders of magnitude. The precipitation and transformation kinetics are examined in situ by differential scanning calorimetry. The differential scanning calorimetry cooling curves show a complex superposition of multiple reactions. The reactions cover a temperature range of about 800 K. To assign some distinct reactions to certain temperature ranges, a defined step quenching method has been applied. Extensive investigations on the resulting microstructure were performed by optical microscopy, scanning electron microscopy, and transmission electron microscopy. It is found that numerous structural features evolve during cooling (depending on the cooling rate), including formation of α-Cu grains, precipitation of several types of secondary κ-precipitates. The microstructural development of these κI, κII, and κIII precipitates is more complex, as these particles are found to contain multiple types of tertiary phase particles. Tthe development of the microstructure is correlated with the resulting mechanical properties, in a way that the hardness is tested after cooling at different rates.
{"title":"Micro- and nanostructural evolution of copper bronze CuAl10Ni5Fe5 during cooling from solution treatments","authors":"Hannes Fröck , Benjamin Milkereit , Jette Broer , Armin Springer , Sigurd Wenner , Kevin Oldenburg , Tobias Kruse , Christian Kloetzer-Freese , Olaf Kessler","doi":"10.1016/j.matchar.2025.114795","DOIUrl":"10.1016/j.matchar.2025.114795","url":null,"abstract":"<div><div>The Cu<img>Al bronze alloy CuAl10Ni5Fe5 has been widely used in maritime components, such as large ship propellers, for many decades because of its excellent corrosion resistance and mechanical properties. The alloy is mainly manufactured by casting. In the present work, its micro- and nanostructural development during cooling from solution treatments is investigated. The cooling rates were varied over four orders of magnitude. The precipitation and transformation kinetics are examined in situ by differential scanning calorimetry. The differential scanning calorimetry cooling curves show a complex superposition of multiple reactions. The reactions cover a temperature range of about 800 K. To assign some distinct reactions to certain temperature ranges, a defined step quenching method has been applied. Extensive investigations on the resulting microstructure were performed by optical microscopy, scanning electron microscopy, and transmission electron microscopy. It is found that numerous structural features evolve during cooling (depending on the cooling rate), including formation of α-Cu grains, precipitation of several types of secondary κ-precipitates. The microstructural development of these κ<sub>I</sub>, κ<sub>II</sub>, and κ<sub>III</sub> precipitates is more complex, as these particles are found to contain multiple types of tertiary phase particles. Tthe development of the microstructure is correlated with the resulting mechanical properties, in a way that the hardness is tested after cooling at different rates.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114795"},"PeriodicalIF":4.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanostructured bainitic steels exhibit high strength and toughness. A potential approach to improving their toughness is enhancing the chemical or mechanical stability of blocky austenite while maintaining the volume fractions of austenite and bainitic ferrite. This study investigates the effects of ausforming at 250 °C with a 20 % strain on the microstructure and stability of blocky austenite and contrasts these effects with non-ausformed bainite. The stability of austenite is assessed by cryogenic treatments. Two types of bainitic ferrite are observed in ausformed bainite. The fine bainitic ferrite forms around austenite twins and has the Kurdjumov-Sachs (K-S) orientation relationship with austenite. In contrast, the coarse bainitic ferrite, which has the Nishiyama-Wassermann (N-W) orientation relationship, creates an interlocking microstructure where blocky austenite is refined and has a high dislocation density. The blocky austenite in the ausformed bainite remains untransformed after the cryogenic treatment, while some blocky austenite in non-ausformed bainite transforms into martensite. These results suggest that two types of bainitic ferrite may form via different mechanisms, and that the interlocking microstructure enhances mechanical stability of blocky austenite by dislocations and block size refinement.
{"title":"Effects of ausforming on the microstructure and stability of blocky austenite in nanostructured bainite","authors":"Po-Yen Tung , Shao-Pu Tsai , Yu-Ting Tsai , Jer-Ren Yang","doi":"10.1016/j.matchar.2025.114792","DOIUrl":"10.1016/j.matchar.2025.114792","url":null,"abstract":"<div><div>Nanostructured bainitic steels exhibit high strength and toughness. A potential approach to improving their toughness is enhancing the chemical or mechanical stability of blocky austenite while maintaining the volume fractions of austenite and bainitic ferrite. This study investigates the effects of ausforming at 250 °C with a 20 % strain on the microstructure and stability of blocky austenite and contrasts these effects with non-ausformed bainite. The stability of austenite is assessed by cryogenic treatments. Two types of bainitic ferrite are observed in ausformed bainite. The fine bainitic ferrite forms around austenite twins and has the Kurdjumov-Sachs (K-S) orientation relationship with austenite. In contrast, the coarse bainitic ferrite, which has the Nishiyama-Wassermann (N-W) orientation relationship, creates an interlocking microstructure where blocky austenite is refined and has a high dislocation density. The blocky austenite in the ausformed bainite remains untransformed after the cryogenic treatment, while some blocky austenite in non-ausformed bainite transforms into martensite. These results suggest that two types of bainitic ferrite may form via different mechanisms, and that the interlocking microstructure enhances mechanical stability of blocky austenite by dislocations and block size refinement.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114792"},"PeriodicalIF":4.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-30DOI: 10.1016/j.matchar.2025.114769
Qian Liu , Wanting Sun , Shuangjie Chu , Yuqian Wang , Bohao Zhou , Hao Wang , Bo Mao
In this study, the thermal stability of gradient microstructure in the commercial AZ31B magnesium (Mg) alloy processed by laser shock peening (LSP) is systematically explored using quasi-in-situ electron backscatter diffraction (EBSD) measurement. The mechanisms of grain growth and twinning evolution of LSP-processed AZ31B Mg alloy during the annealing treatment at 300 °C are revealed. The experimental results demonstrate that there is a significant transformation of a gradient twinning microstructure into an almost twin-free microstructure, and the trend of grain growth is associated with LSP-induced strain energy storage. From the topmost surface to the sublayer of LSP-processed sample, the grain growth is mainly driven by the migrations of twin boundaries (TBs) and high-angle grain boundaries (HAGBs), respectively, which is attributed to the reduced accumulated strain energy along the LSP direction. It was demonstrated that the {102} tension twins possess the capability to engulf non-corresponding parent phases, which transcends the conventional understanding that twins interact solely with their corresponding parent grains. The twins not only interact with the parent grain but also have the capacity to engulf twins of adjacent parent grains. In contrast, the isolated twins within the parent grains struggle to grow during annealing, indicating that {102} tension twins have excellent thermal stability. The findings of this work can contribute to an in-depth understanding of the thermal stability and the grain growth mechanisms of LSP-induced gradient twinning microstructure in Mg alloys and provide the potential for the microstructure optimization to improve the comprehensive mechanical properties.
{"title":"Quasi-in-situ EBSD study of the thermal stability of gradient twinning microstructure of an AZ31B magnesium alloy processed by laser shock peening","authors":"Qian Liu , Wanting Sun , Shuangjie Chu , Yuqian Wang , Bohao Zhou , Hao Wang , Bo Mao","doi":"10.1016/j.matchar.2025.114769","DOIUrl":"10.1016/j.matchar.2025.114769","url":null,"abstract":"<div><div>In this study, the thermal stability of gradient microstructure in the commercial AZ31B magnesium (Mg) alloy processed by laser shock peening (LSP) is systematically explored using quasi-in-situ electron backscatter diffraction (EBSD) measurement. The mechanisms of grain growth and twinning evolution of LSP-processed AZ31B Mg alloy during the annealing treatment at 300 °C are revealed. The experimental results demonstrate that there is a significant transformation of a gradient twinning microstructure into an almost twin-free microstructure, and the trend of grain growth is associated with LSP-induced strain energy storage. From the topmost surface to the sublayer of LSP-processed sample, the grain growth is mainly driven by the migrations of twin boundaries (TBs) and high-angle grain boundaries (HAGBs), respectively, which is attributed to the reduced accumulated strain energy along the LSP direction. It was demonstrated that the {10<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>2} tension twins possess the capability to engulf non-corresponding parent phases, which transcends the conventional understanding that twins interact solely with their corresponding parent grains. The twins not only interact with the parent grain but also have the capacity to engulf twins of adjacent parent grains. In contrast, the isolated twins within the parent grains struggle to grow during annealing, indicating that {10<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>2} tension twins have excellent thermal stability. The findings of this work can contribute to an in-depth understanding of the thermal stability and the grain growth mechanisms of LSP-induced gradient twinning microstructure in Mg alloys and provide the potential for the microstructure optimization to improve the comprehensive mechanical properties.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114769"},"PeriodicalIF":4.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1016/j.matchar.2025.114785
Svetlana Buyakova, Igor Fotin, Yuriy Mirovoy, Alexander Burlachenko, Vasiliy Shmakov, Ekaterina Abdulmenova, Ales Buyakov
Fracture toughness of ZrC-Al2O3 composites with gradient layered structure have been studied. The outer layers were represented purely by ZrC and Al2O3, and the intermediate layers were represented by their composites. It is shown that a crack nucleated in the ZrC experiences deflections and bifurcations under the action of residual compressive stresses. In the case of crack nucleation in Al2O3 tensile microstresses create favorable conditions for its development. It was found that increasing the number of intermediate layers leads to equalization of residual microstresses, reducing the fracture toughness. Thus, there is a compromise when creating gradient composites based on components with a noticeable difference in the coefficient of thermal expansion values: increasing the number of layers provide a gradient transition from one phase to another, reduces the risk of structure defects formation. Reducing the number of layers carries the risk of delamination, but is more efficient in dissipation of crack energy.
{"title":"Fracture toughness control of gradient layered ZrC–Al2O3 ceramic composites","authors":"Svetlana Buyakova, Igor Fotin, Yuriy Mirovoy, Alexander Burlachenko, Vasiliy Shmakov, Ekaterina Abdulmenova, Ales Buyakov","doi":"10.1016/j.matchar.2025.114785","DOIUrl":"10.1016/j.matchar.2025.114785","url":null,"abstract":"<div><div>Fracture toughness of ZrC-Al<sub>2</sub>O<sub>3</sub> composites with gradient layered structure have been studied. The outer layers were represented purely by ZrC and Al<sub>2</sub>O<sub>3</sub>, and the intermediate layers were represented by their composites. It is shown that a crack nucleated in the ZrC experiences deflections and bifurcations under the action of residual compressive stresses. In the case of crack nucleation in Al<sub>2</sub>O<sub>3</sub> tensile microstresses create favorable conditions for its development. It was found that increasing the number of intermediate layers leads to equalization of residual microstresses, reducing the fracture toughness. Thus, there is a compromise when creating gradient composites based on components with a noticeable difference in the coefficient of thermal expansion values: increasing the number of layers provide a gradient transition from one phase to another, reduces the risk of structure defects formation. Reducing the number of layers carries the risk of delamination, but is more efficient in dissipation of crack energy.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114785"},"PeriodicalIF":4.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1016/j.matchar.2025.114787
Jiaqi Hou , Jiaping Zhang , Shiyu Kou , Ruicong Chen , Xiaohui Yang , Longteng Bai , Qiangang Fu
A new route was proposed to fabricate ZrC-SiC coatings on carbon/carbon composites by slurry dipping and chemical vapor reaction methods. The cyclic ablation resistance of the coatings with different thicknesses was investigated using an oxyacetylene torch. During cyclic ablation, a moderate coating thickness can help relieve the residual thermal stress, decreasing the generation of cracks. In addition, the ZrO2 skeleton pinned the SiO2 glass and the molten Zr-Si-O glass that can work as a protective layer against ablation, and its anti-ablation behavior changed from “surface ablation” to “internal ablation” with increasing ablation time and cycles. After ablation for 180 s (2 cycles, 90 s for each), the ZrC-SiC coating with a thickness about 220 μm exhibited the best cyclic ablation resistance with the mass and linear ablation rates of 0.40 × 10−3 mg/s·mm2 and − 0.39 μm/s, respectively.
{"title":"Optimizing and ablation behavior of ZrC-SiC coating prepared by a coupling process","authors":"Jiaqi Hou , Jiaping Zhang , Shiyu Kou , Ruicong Chen , Xiaohui Yang , Longteng Bai , Qiangang Fu","doi":"10.1016/j.matchar.2025.114787","DOIUrl":"10.1016/j.matchar.2025.114787","url":null,"abstract":"<div><div>A new route was proposed to fabricate ZrC-SiC coatings on carbon/carbon composites by slurry dipping and chemical vapor reaction methods. The cyclic ablation resistance of the coatings with different thicknesses was investigated using an oxyacetylene torch. During cyclic ablation, a moderate coating thickness can help relieve the residual thermal stress, decreasing the generation of cracks. In addition, the ZrO<sub>2</sub> skeleton pinned the SiO<sub>2</sub> glass and the molten Zr-Si-O glass that can work as a protective layer against ablation, and its anti-ablation behavior changed from “surface ablation” to “internal ablation” with increasing ablation time and cycles. After ablation for 180 s (2 cycles, 90 s for each), the ZrC-SiC coating with a thickness about 220 μm exhibited the best cyclic ablation resistance with the mass and linear ablation rates of 0.40 × 10<sup>−3</sup> mg/s·mm<sup>2</sup> and − 0.39 μm/s, respectively.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114787"},"PeriodicalIF":4.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1016/j.matchar.2025.114789
M.S. Lyrio , H.R. Oliveira , M.J.R. Sandim , V. Devulapalli , H.R.Z. Sandim
Abnormal grain growth is a fundamental phenomenon in the processing of grain-oriented electrical steels. The presence of inhibitors, strong texture, and reduced sheet thickness are key factors that contribute to its occurrence. In this work, a grain-oriented electrical steel (Fe-4wt%Si) was obtained using laser powder bed fusion (LPBF) additive manufacturing and subsequent thermomechanical processing. The LPBF-processed slabs were built using scanning strategies without rotation (0°) and with rotations of 45° and 90° between the layers. Subsequently, the slabs were cold rolled to 91 % reduction. Abnormal grain growth occurred during prolonged box annealing at 1200 °C, favored by the coarsening of crystalline SiO2-based nanoparticles that acted as inhibitors of normal grain growth. The influence of the scanning strategy on the as-built texture and the magnetic properties after thermomechanical processing was investigated. Very coarse grain sizes, low porosity and reduced thickness contributed positively to the decrease in magnetic losses. The deviation of Goss grains from the ideal orientation was smaller for samples without rotation (0o), indicating that this scanning strategy generates textures closer to the desired ones (Goss and η fiber). This strategy provided the lowest magnetic losses and the best magnetic properties among the laser scanning strategies investigated.
{"title":"Effect of the scanning strategy on texture of grain-oriented electrical steel (Fe-4wt%Si) processed via laser powder-bed fusion and subsequent thermomechanical processing","authors":"M.S. Lyrio , H.R. Oliveira , M.J.R. Sandim , V. Devulapalli , H.R.Z. Sandim","doi":"10.1016/j.matchar.2025.114789","DOIUrl":"10.1016/j.matchar.2025.114789","url":null,"abstract":"<div><div>Abnormal grain growth is a fundamental phenomenon in the processing of grain-oriented electrical steels. The presence of inhibitors, strong texture, and reduced sheet thickness are key factors that contribute to its occurrence. In this work, a grain-oriented electrical steel (Fe-4wt%Si) was obtained using laser powder bed fusion (LPBF) additive manufacturing and subsequent thermomechanical processing. The LPBF-processed slabs were built using scanning strategies without rotation (0°) and with rotations of 45° and 90° between the layers. Subsequently, the slabs were cold rolled to 91 % reduction. Abnormal grain growth occurred during prolonged box annealing at 1200 °C, favored by the coarsening of crystalline SiO<sub>2</sub>-based nanoparticles that acted as inhibitors of normal grain growth. The influence of the scanning strategy on the as-built texture and the magnetic properties after thermomechanical processing was investigated. Very coarse grain sizes, low porosity and reduced thickness contributed positively to the decrease in magnetic losses. The deviation of Goss grains from the ideal orientation was smaller for samples without rotation (0<sup>o</sup>), indicating that this scanning strategy generates textures closer to the desired ones (Goss and η fiber). This strategy provided the lowest magnetic losses and the best magnetic properties among the laser scanning strategies investigated.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114789"},"PeriodicalIF":4.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1016/j.matchar.2025.114786
Hanqun Wu , Liping Deng , Xincheng Pan , Bingshu Wang , Hongliang Xiang
The laminated carbon-nanotubes/Cu (CNTs/Cu) composites were fabricated by electrophoretic deposition (EPD), spark plasma sintering (SPS), and hot rolling to achieve a good combination of properties. The microstructure, mechanical properties, and electrical conductivity were investigated, and the strengthening mechanism was discussed. Results indicated that functional groups were introduced onto the surface of CNTs after acid treatment, enabling the formation of an optimal CNT deposition morphology on the Cu matrix at an electrophoretic deposition voltage of 75 V. The sintered CNTs/Cu composite exhibits a laminated structure with coarse grains and randomly distributed textures. Compared to sintered pure Cu, the sintered composite demonstrates a 42.07 % increase in tensile strength and a 17.8 % improvement in elongation. And the electrical conductivity reaches 93.05 % of the International Annealed Copper Standard (IACS). Subsequent hot rolling refined the grains and reoriented the texture to deformation textures. The hot-rolled composites achieve a tensile strength of 355 MPa, an elongation of 12.2 %, and a conductivity of 85.53 % IACS. The strengthening mechanisms of CNTs/Cu composites involve grain refinement, load transfer, and thermal mismatch strengthening, with grain refinement as the primary factor. Grain refinement, crack deflection, and bridging-pullout of CNTs are mainly responsible for the good combination of strength, ductility and electrical conductivity.
{"title":"Study on the microstructure, properties and strengthening mechanisms of electrophoretic deposited carbon-nanotubes/Cu composites","authors":"Hanqun Wu , Liping Deng , Xincheng Pan , Bingshu Wang , Hongliang Xiang","doi":"10.1016/j.matchar.2025.114786","DOIUrl":"10.1016/j.matchar.2025.114786","url":null,"abstract":"<div><div>The laminated carbon-nanotubes/Cu (CNTs/Cu) composites were fabricated by electrophoretic deposition (EPD), spark plasma sintering (SPS), and hot rolling to achieve a good combination of properties. The microstructure, mechanical properties, and electrical conductivity were investigated, and the strengthening mechanism was discussed. Results indicated that functional groups were introduced onto the surface of CNTs after acid treatment, enabling the formation of an optimal CNT deposition morphology on the Cu matrix at an electrophoretic deposition voltage of 75 V. The sintered CNTs/Cu composite exhibits a laminated structure with coarse grains and randomly distributed textures. Compared to sintered pure Cu, the sintered composite demonstrates a 42.07 % increase in tensile strength and a 17.8 % improvement in elongation. And the electrical conductivity reaches 93.05 % of the International Annealed Copper Standard (IACS). Subsequent hot rolling refined the grains and reoriented the texture to deformation textures. The hot-rolled composites achieve a tensile strength of 355 MPa, an elongation of 12.2 %, and a conductivity of 85.53 % IACS. The strengthening mechanisms of CNTs/Cu composites involve grain refinement, load transfer, and thermal mismatch strengthening, with grain refinement as the primary factor. Grain refinement, crack deflection, and bridging-pullout of CNTs are mainly responsible for the good combination of strength, ductility and electrical conductivity.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114786"},"PeriodicalIF":4.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1016/j.matchar.2025.114774
Yunxiu Lian, Wei Dong, Fumin Xu
Metallic materials for energy storage offer promising prospects for elevating energy conservation and efficiency. In this study, we successfully synthesized the AlSi alloy particles with different silicon contents as metallic phase-change materials for high-temperature thermal energy storage by pulsated orifice ejection method (POEM). These particles were crucial to enhancing thermal storage performance, due to their smooth and dense surfaces, narrow particle size distributions, high sphericities, high purities, and uniform and fine-grained microstructures. They exhibited excellent thermal stability, high thermal conductivity, and high latent heat capacity. The melting enthalpy of the particles could reach a maximum of 505.41 J·g−1. And the corresponding solidification enthalpy was 519.18 J·g−1. Notably, the particles maintained high energy storage density and strong structural stability over multiple thermal cycles. The POEM-prepared particles demonstrate a significant potential in the field of phase-change energy storage, thus leading to substantial advantages in practical applications.
{"title":"Microstructures and thermal properties of mono-sized AlSi particles prepared by pulsated orifice ejection method","authors":"Yunxiu Lian, Wei Dong, Fumin Xu","doi":"10.1016/j.matchar.2025.114774","DOIUrl":"10.1016/j.matchar.2025.114774","url":null,"abstract":"<div><div>Metallic materials for energy storage offer promising prospects for elevating energy conservation and efficiency. In this study, we successfully synthesized the Al<img>Si alloy particles with different silicon contents as metallic phase-change materials for high-temperature thermal energy storage by pulsated orifice ejection method (POEM). These particles were crucial to enhancing thermal storage performance, due to their smooth and dense surfaces, narrow particle size distributions, high sphericities, high purities, and uniform and fine-grained microstructures. They exhibited excellent thermal stability, high thermal conductivity, and high latent heat capacity. The melting enthalpy of the particles could reach a maximum of 505.41 J·g<sup>−1</sup>. And the corresponding solidification enthalpy was 519.18 J·g<sup>−1</sup>. Notably, the particles maintained high energy storage density and strong structural stability over multiple thermal cycles. The POEM-prepared particles demonstrate a significant potential in the field of phase-change energy storage, thus leading to substantial advantages in practical applications.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"221 ","pages":"Article 114774"},"PeriodicalIF":4.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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