{"title":"Analysis of Existing States of Co-Deposited Hydrogen in Electrodeposited Pd Films","authors":"Tomoya Hashimoto, Tomoya Nakamura, Naoki Fukumuro, Shinji Yae","doi":"10.2320/matertrans.mt-m2023076","DOIUrl":"https://doi.org/10.2320/matertrans.mt-m2023076","url":null,"abstract":"","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pd-loaded perovskite composite manganese oxide (Pd/AMnO3, A = Ca, Sr, La) catalysts were prepared by coprecipitation method, in order to reveal metal-support interaction (MSI). Particulate PdO with sizes of a few ten nanometers were randomly formed on CaMnO3. On the other hand, fibrous PdO with diameter approximately 20 nm was formed on LaMnO3. Both shape of PdO were formed on SrMnO3. HAXPES measurement showed a down shift of valence band of deposited PdO depending on the composite manganese oxide. Our characterization indicates that the MSI at Pd–AMnO3 interface affects not only the shape but the electronic structure of deposited PdO on AMnO3. The CO oxidation activity was in order of Pd/LaMnO3 > Pd/SrMnO3 > Pd/CaMnO3, which corresponds to the order of the PdO valence band shift trend. We proposed that the observed correlation between the valence band shift and the CO oxidation activity for Pd/AMnO3 can be understood in terms of the CO adsorption strength.
采用共沉淀法制备了负载Pd的钙钛矿复合氧化锰(Pd/AMnO3, A = Ca, Sr, La)催化剂，以揭示金属-载体相互作用(MSI)。在CaMnO3上随机形成了几十纳米大小的PdO颗粒。另一方面，在LaMnO3上形成直径约20 nm的纤维状PdO。两种形状的PdO均在SrMnO3上形成。HAXPES测量表明，沉积的PdO的价带随复合氧化锰的不同而下降。我们的表征表明，Pd-AMnO3界面的MSI不仅影响沉积在AMnO3上的PdO的形状，而且影响其电子结构。CO的氧化活性依次为Pd/LaMnO3 > Pd/SrMnO3 > Pd/CaMnO3，与PdO的价带移位趋势一致。我们提出，观察到的价带位移与Pd/AMnO3的CO氧化活性之间的相关性可以用CO吸附强度来理解。
{"title":"Metal-Support Interaction at Palladium-Composite Manganese Oxide Interface and CO Oxidation Activity","authors":"Toyokazu Tanabe, Kazuma Aso, Shugoro Tsutsumi, Seiya Shimono, Saburo Hosokawa","doi":"10.2320/matertrans.mt-mh2022012","DOIUrl":"https://doi.org/10.2320/matertrans.mt-mh2022012","url":null,"abstract":"Pd-loaded perovskite composite manganese oxide (Pd/AMnO3, A = Ca, Sr, La) catalysts were prepared by coprecipitation method, in order to reveal metal-support interaction (MSI). Particulate PdO with sizes of a few ten nanometers were randomly formed on CaMnO3. On the other hand, fibrous PdO with diameter approximately 20 nm was formed on LaMnO3. Both shape of PdO were formed on SrMnO3. HAXPES measurement showed a down shift of valence band of deposited PdO depending on the composite manganese oxide. Our characterization indicates that the MSI at Pd–AMnO3 interface affects not only the shape but the electronic structure of deposited PdO on AMnO3. The CO oxidation activity was in order of Pd/LaMnO3 > Pd/SrMnO3 > Pd/CaMnO3, which corresponds to the order of the PdO valence band shift trend. We proposed that the observed correlation between the valence band shift and the CO oxidation activity for Pd/AMnO3 can be understood in terms of the CO adsorption strength.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effectiveness of a corrosion repair technique consisting of laser cleaning and cold spraying was investigated. The effect of laser pulse frequency on the removal of surface corrosion on steel specimens was analyzed. Subsequently, a zinc coating was cold-sprayed on specimens cleaned of surface corrosion using conventional disc grinder and laser methods. Furthermore, salt spray tests were conducted to compare the corrosion protection performance of the zinc coating on these specimens. The results showed that laser cleaning can effectively remove surface corrosion and that a laser pulse frequency of 15 kHz is more effective than that of 40 kHz for removing the surface oxide layer. A comparison of cold-sprayed zinc coatings on laser-cleaned and non-treated specimens indicated that surface oxidation during laser treatment may negatively affect zinc deposition efficiency. The zinc coating on the laser-cleaned specimen was more than twice as thick as that on the conventionally cleaned specimen, and the coating–specimen interface maintained good adhesion after a 168 h salt spray test. Although no corrosion was observed in both steel specimens after the salt spray test, cracking of the remaining corroded areas on the substrate and delamination of the coating occurred in the conventionally cleaned specimen.
{"title":"Suggestion of a New Repair Technique for Steel Structures by Low-Pressure Cold Spray and Laser Cleaning","authors":"Tomonori Hatori, Hiroki Saito, Yuji Ichikawa, Kazuhiro Ogawa, Yuichi Kato, Kosaku Motomura, Michito Nakano, Norimichi Yamashita","doi":"10.2320/matertrans.mt-t2023001","DOIUrl":"https://doi.org/10.2320/matertrans.mt-t2023001","url":null,"abstract":"The effectiveness of a corrosion repair technique consisting of laser cleaning and cold spraying was investigated. The effect of laser pulse frequency on the removal of surface corrosion on steel specimens was analyzed. Subsequently, a zinc coating was cold-sprayed on specimens cleaned of surface corrosion using conventional disc grinder and laser methods. Furthermore, salt spray tests were conducted to compare the corrosion protection performance of the zinc coating on these specimens. The results showed that laser cleaning can effectively remove surface corrosion and that a laser pulse frequency of 15 kHz is more effective than that of 40 kHz for removing the surface oxide layer. A comparison of cold-sprayed zinc coatings on laser-cleaned and non-treated specimens indicated that surface oxidation during laser treatment may negatively affect zinc deposition efficiency. The zinc coating on the laser-cleaned specimen was more than twice as thick as that on the conventionally cleaned specimen, and the coating–specimen interface maintained good adhesion after a 168 h salt spray test. Although no corrosion was observed in both steel specimens after the salt spray test, cracking of the remaining corroded areas on the substrate and delamination of the coating occurred in the conventionally cleaned specimen.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.2320/matertrans.mt-mg2022026
Nguyen Dang Co, Bui Dai Phat, Phan Van Khai, Tran Quang Dat, Ho Thi Anh, Nguyen Tran Ha, Le Viet Cuong, Nguyen Huy Tiep, Nguyen Thi Minh Hong, Dang Duc Dung, Ngo Duc Quan, Tran Mau Danh, Phan The Long, Pham Duc Thang, Bui Dinh Tu
The combination of two dielectric-magnetic components in the same composite has been shown to significantly improve the effectiveness of electromagnetic (EM) shielding and microwave absorption (MWA) because they have both a combination of high dielectric and magnetic losses and good impedance matching. The novel Bi1/2(Na0.8K0.2)1/2TiO3/Fe3O4 (BNKT/Fe3O4) composite has been successfully synthesized by a two-step method with wide effective absorption bandwidth (EAB = 16 GHz) in the high-frequency (2–18 GHz). It was evident that the MWA efficiency of the BNKT/Fe3O4 composite has been significantly improved compared with pure Bi1/2(Na0.8K0.2)1/2TiO3 or Fe3O4 materials. In addition, the BNKT/Fe3O4 composite could achieve reflection loss (RL = −39.41 dB, ∼99.99% at 10.16 GHz) with a sample thickness optimal (d = 4.7 mm). This work shows that the novel BNKT/Fe3O4 composite has excellent MWA properties, all contributing to a potential candidate in the electromagnetic wave absorption and shielding fields.
{"title":"Synthesis and Microwave Absorption Properties of Novel Bi<sub>1/2</sub>(Na<sub>0.8</sub>K<sub>0.2</sub>)<sub>1/2</sub>TiO<sub>3</sub>/Fe<sub>3</sub>O<sub>4</sub> Composite","authors":"Nguyen Dang Co, Bui Dai Phat, Phan Van Khai, Tran Quang Dat, Ho Thi Anh, Nguyen Tran Ha, Le Viet Cuong, Nguyen Huy Tiep, Nguyen Thi Minh Hong, Dang Duc Dung, Ngo Duc Quan, Tran Mau Danh, Phan The Long, Pham Duc Thang, Bui Dinh Tu","doi":"10.2320/matertrans.mt-mg2022026","DOIUrl":"https://doi.org/10.2320/matertrans.mt-mg2022026","url":null,"abstract":"The combination of two dielectric-magnetic components in the same composite has been shown to significantly improve the effectiveness of electromagnetic (EM) shielding and microwave absorption (MWA) because they have both a combination of high dielectric and magnetic losses and good impedance matching. The novel Bi1/2(Na0.8K0.2)1/2TiO3/Fe3O4 (BNKT/Fe3O4) composite has been successfully synthesized by a two-step method with wide effective absorption bandwidth (EAB = 16 GHz) in the high-frequency (2–18 GHz). It was evident that the MWA efficiency of the BNKT/Fe3O4 composite has been significantly improved compared with pure Bi1/2(Na0.8K0.2)1/2TiO3 or Fe3O4 materials. In addition, the BNKT/Fe3O4 composite could achieve reflection loss (RL = −39.41 dB, ∼99.99% at 10.16 GHz) with a sample thickness optimal (d = 4.7 mm). This work shows that the novel BNKT/Fe3O4 composite has excellent MWA properties, all contributing to a potential candidate in the electromagnetic wave absorption and shielding fields.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Resistance spot welding is used in the assembly of automobile bodies. The use of high tensile strength steel plates in automobile bodies is expanding, and there is a need to develop a welding process that improves the joint strength per resistance spot weld point. To improve the joint strength per resistance spot weld, resistance spot welding can be combined with other joining methods, such as the WeldBond method. As an additional joining method around the nugget, other than using adhesives as in the WeldBond method, brazing can be used to obtain a strong joint without melting the base metal. In this paper, it was proposed that the joint strength can be enhanced by using resistance spot welding and brazing or soldering based on the rule of mixture. And, based on this concept, effect of additional joint around a nugget, such as brazing or soldering, on rotational deformation of joint part and tensile shear strength of resistance spot welded lap joint was examined.
{"title":"Effect of Combined Use of Brazing or Soldering around the Nugget on Tensile Shear Strength of Resistance Spot Welded Lap Joint","authors":"Takanori Kitamura, Tetsuya Akiyama, Atsuro Uemura, Chinatsu Mihara","doi":"10.2320/matertrans.mt-m2023096","DOIUrl":"https://doi.org/10.2320/matertrans.mt-m2023096","url":null,"abstract":"Resistance spot welding is used in the assembly of automobile bodies. The use of high tensile strength steel plates in automobile bodies is expanding, and there is a need to develop a welding process that improves the joint strength per resistance spot weld point. To improve the joint strength per resistance spot weld, resistance spot welding can be combined with other joining methods, such as the WeldBond method. As an additional joining method around the nugget, other than using adhesives as in the WeldBond method, brazing can be used to obtain a strong joint without melting the base metal. In this paper, it was proposed that the joint strength can be enhanced by using resistance spot welding and brazing or soldering based on the rule of mixture. And, based on this concept, effect of additional joint around a nugget, such as brazing or soldering, on rotational deformation of joint part and tensile shear strength of resistance spot welded lap joint was examined.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135063171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multinary Cu2ZnSnS4 (CZTS)-based materials have attracted considerable attention for thermoelectric (TE) power generation owing to their cost-effectiveness and abundance. The device structure of the CZTS/Au diffusion barrier layer was effective in impeding chemical diffusion during operation; however, its interfacial contact resistance was relatively higher than that of the Bi2Te3 device. We report the discovery of p-type CZTS single crystals with a record-high dimensionless figure of merit (ZT) of 1.6 at 800 K and TE conversion efficiency of ∼4% at a temperature difference of 473 K, which is based on the Te-free concept. This study demonstrated the potential of CZTS-based TE materials for environment-friendly TE power generation.
{"title":"Thermoelectric Conversion Efficiency of 4% in Environmental-Friendly Kesterite Single Crystal","authors":"Akira Nagaoka, Katsuma Nagatomo, Koki Nakashima, Yuichi Hirai, Yasuyuki Ota, Kenji Yoshino, Kensuke Nishioka","doi":"10.2320/matertrans.mt-e2023002","DOIUrl":"https://doi.org/10.2320/matertrans.mt-e2023002","url":null,"abstract":"Multinary Cu2ZnSnS4 (CZTS)-based materials have attracted considerable attention for thermoelectric (TE) power generation owing to their cost-effectiveness and abundance. The device structure of the CZTS/Au diffusion barrier layer was effective in impeding chemical diffusion during operation; however, its interfacial contact resistance was relatively higher than that of the Bi2Te3 device. We report the discovery of p-type CZTS single crystals with a record-high dimensionless figure of merit (ZT) of 1.6 at 800 K and TE conversion efficiency of ∼4% at a temperature difference of 473 K, which is based on the Te-free concept. This study demonstrated the potential of CZTS-based TE materials for environment-friendly TE power generation.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the rapid national development of various countries, organic dyes have been applied in manufacturing products such as leather, textiles, paper, and cosmetics. However, the wastewater produced by these industries is harmful to the environment and organisms. Moreover, organic dyes contain toxic carcinogens and cause the reduction of the oxygen content in water, which is harmful to nature and the water resources people use. Photodegradation is a low-cost, highly efficient, and low-energy way to remove these substances. Zinc-based materials were applied as a degradation catalyst in this study. ZnO–ZnCr2O4/g-C3N4 nanocomposites were fabricated by the urea combustion method and used as photocatalysts for rhodamine B (RhB) degradation under ultraviolet A (UVA) light irradiation. ZnO–ZnCr2O4/g-C3N4 was investigated by XRD, FESEM, BET, UV-Vis, and TEM to confirm the crystalline microstructure. Based on the various annealing temperatures of ZnO–ZnCr2O4/g-C3N4 nanocomposite, the specific surface area varied from 36.33 m2/g to 107.55 m2/g. In addition, the photocatalytic activities of ZnO–ZnCr2O4/g-C3N4 nanocrystals were investigated through the degradation of RhB under UV light for 12 hours. After 12 hours, 95.45% of the RhB was degraded under UV light irradiation. ZnO–ZnCr2O4/g-C3N4 nanocomposites annealed at 500°C exhibited the highest rate constant, up to 6.11 × 10−3 min−1, and ZnO–ZnCr2O4/g-C3N4 revealed excellent stability based on the results of the cyclic test.
{"title":"Photodegradation under Ultraviolet Light Irradiation of RhB by ZnO–ZnCr<sub>2</sub>O<sub>4</sub>/g-C<sub>3</sub>N<sub>4</sub> Nanocomposites Fabricated by Urea Combustion Method","authors":"Chung-Lun Yu, Subramanian Sakthinathan, Chia-Cheng Lin, Yi-Hsuan Lee, Te-Wei Chiu","doi":"10.2320/matertrans.mt-mh2022009","DOIUrl":"https://doi.org/10.2320/matertrans.mt-mh2022009","url":null,"abstract":"Due to the rapid national development of various countries, organic dyes have been applied in manufacturing products such as leather, textiles, paper, and cosmetics. However, the wastewater produced by these industries is harmful to the environment and organisms. Moreover, organic dyes contain toxic carcinogens and cause the reduction of the oxygen content in water, which is harmful to nature and the water resources people use. Photodegradation is a low-cost, highly efficient, and low-energy way to remove these substances. Zinc-based materials were applied as a degradation catalyst in this study. ZnO–ZnCr2O4/g-C3N4 nanocomposites were fabricated by the urea combustion method and used as photocatalysts for rhodamine B (RhB) degradation under ultraviolet A (UVA) light irradiation. ZnO–ZnCr2O4/g-C3N4 was investigated by XRD, FESEM, BET, UV-Vis, and TEM to confirm the crystalline microstructure. Based on the various annealing temperatures of ZnO–ZnCr2O4/g-C3N4 nanocomposite, the specific surface area varied from 36.33 m2/g to 107.55 m2/g. In addition, the photocatalytic activities of ZnO–ZnCr2O4/g-C3N4 nanocrystals were investigated through the degradation of RhB under UV light for 12 hours. After 12 hours, 95.45% of the RhB was degraded under UV light irradiation. ZnO–ZnCr2O4/g-C3N4 nanocomposites annealed at 500°C exhibited the highest rate constant, up to 6.11 × 10−3 min−1, and ZnO–ZnCr2O4/g-C3N4 revealed excellent stability based on the results of the cyclic test.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.2320/matertrans.mt-m2023093
Ivan Lobzenko, Tomohito Tsuru, Hideki Mori, Daisuke Matsunaka, Yoshinori Shiihara
Atomic stress, utilized in molecular mechanics and molecular dynamics, is valuable in analyzing complex phenomena such as heat transfer, crack propagation and void growth. However, traditional modeling techniques designed for large-scale systems may lack the precision achievable through first-principles calculations. To overcome this limitation, we propose an approach based on artificial neural network (ANN) potentials to compute atomic stress. A crucial aspect of this method is the use of central force decomposition to derive the atomic stress tensor of the ANN potential, ensuring compliance with the balance between linear and angular momentum. By comparing atomic stress calculations for surface systems in Fe and Al using the ANN and embedded-atom (EAM) potentials, we demonstrate that the ANN potential accurately reproduces the stress oscillations near the surface layer predicted by first-principles calculations. This scheme allows us to evaluate atomic stress with nearly the same accuracy as first-principles calculations, even in large-scale models with complex geometries and defect structures.
{"title":"Implementation of Atomic Stress Calculations with Artificial Neural Network Potentials","authors":"Ivan Lobzenko, Tomohito Tsuru, Hideki Mori, Daisuke Matsunaka, Yoshinori Shiihara","doi":"10.2320/matertrans.mt-m2023093","DOIUrl":"https://doi.org/10.2320/matertrans.mt-m2023093","url":null,"abstract":"Atomic stress, utilized in molecular mechanics and molecular dynamics, is valuable in analyzing complex phenomena such as heat transfer, crack propagation and void growth. However, traditional modeling techniques designed for large-scale systems may lack the precision achievable through first-principles calculations. To overcome this limitation, we propose an approach based on artificial neural network (ANN) potentials to compute atomic stress. A crucial aspect of this method is the use of central force decomposition to derive the atomic stress tensor of the ANN potential, ensuring compliance with the balance between linear and angular momentum. By comparing atomic stress calculations for surface systems in Fe and Al using the ANN and embedded-atom (EAM) potentials, we demonstrate that the ANN potential accurately reproduces the stress oscillations near the surface layer predicted by first-principles calculations. This scheme allows us to evaluate atomic stress with nearly the same accuracy as first-principles calculations, even in large-scale models with complex geometries and defect structures.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leakage flux in rotor core bridges is a problem specific to interior permanent-magnet (IPM) motors. It is widely known that the partial non-magnetization of bridges reduces the magnetic flux leakage. In a previous study, a process was proposed whereby a part of the silicon steel sheet that bridges after pressing was non-magnetized by melting and mixing Ni–Cr alloy powder with a silicon steel sheet using a laser, and the rotor core was produced by laminating them. However, because the final solidification part had solidification defects, such as cracks and shrinkage cavity, the process was proposed to leave a homogenous part free of solidification defects. Therefore, the area of the improved portion increased. We focused on developing a new alloy for non-magnetic improvement to suppress solidification defects. The improved portion was melted and mixed using a laser with various B contents to obtain a composition of Fe–(15–20) mass%Ni–(15–20) mass%Cr–(2–3) mass%Si–(0–1.6) mass%B. Large cracks and large shrinkage cavity were observed in the boron-free alloy. The cracks and shrinkage cavity decreased with an increase in the B content. The minimization of the area of non-magnetic improvement is possible by suppressing solidification defects. Consequently, the laser processing speed per piece and the amount of expensive nickel were reduced. These new alloys show promise for practical applications in the partial non-magnetization process.
{"title":"Suppression of Solidification Defects in Partial Non-Magnetization Improvement for Silicon Steel","authors":"Norihiko Hamada, Takashi Horikawa, Hironari Mitarai, Katsunari Oikawa, Satoshi Sugimoto","doi":"10.2320/matertrans.mt-maw2023001","DOIUrl":"https://doi.org/10.2320/matertrans.mt-maw2023001","url":null,"abstract":"Leakage flux in rotor core bridges is a problem specific to interior permanent-magnet (IPM) motors. It is widely known that the partial non-magnetization of bridges reduces the magnetic flux leakage. In a previous study, a process was proposed whereby a part of the silicon steel sheet that bridges after pressing was non-magnetized by melting and mixing Ni–Cr alloy powder with a silicon steel sheet using a laser, and the rotor core was produced by laminating them. However, because the final solidification part had solidification defects, such as cracks and shrinkage cavity, the process was proposed to leave a homogenous part free of solidification defects. Therefore, the area of the improved portion increased. We focused on developing a new alloy for non-magnetic improvement to suppress solidification defects. The improved portion was melted and mixed using a laser with various B contents to obtain a composition of Fe–(15–20) mass%Ni–(15–20) mass%Cr–(2–3) mass%Si–(0–1.6) mass%B. Large cracks and large shrinkage cavity were observed in the boron-free alloy. The cracks and shrinkage cavity decreased with an increase in the B content. The minimization of the area of non-magnetic improvement is possible by suppressing solidification defects. Consequently, the laser processing speed per piece and the amount of expensive nickel were reduced. These new alloys show promise for practical applications in the partial non-magnetization process.","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2320/matertrans.mt-m2023043
Yoichi Ikeda, Y. Umemoto, D. Matsumura, T. Tsuji, Yuki Hashimoto, T. Kitazawa, Masaki Fujita
{"title":"Local Atomic Displacements and Sign of the Structural Transformation in Medium-Entropy Alloys Observed in Extended X-ray Absorption Fine Structure Spectra","authors":"Yoichi Ikeda, Y. Umemoto, D. Matsumura, T. Tsuji, Yuki Hashimoto, T. Kitazawa, Masaki Fujita","doi":"10.2320/matertrans.mt-m2023043","DOIUrl":"https://doi.org/10.2320/matertrans.mt-m2023043","url":null,"abstract":"","PeriodicalId":18402,"journal":{"name":"Materials Transactions","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46943208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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