Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was ...Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was performed to prepare a freestanding nanostructured hydrogen evolution reaction(HER)catalyst.The effect of dealloying and addition of Ru to TiCu alloys on the microstructure and HER properties under alkaline conditions was investigated.3 at.%Ru addition in Ti_(40)Cu_(60) decreases the overpotential to reach a current density of 10mA cm^(-2) and Tafel slope of the dealloyed samples to 35 and 34mV dec−1.The improvement of electrocatalytic properties was attributed to the formation of a nanostructure and the modification of the electronic structure of the catalyst.First-principles calculations based on density function theory indicate that Ru decreases the Gibbs free energy of water dissociation.This work presents a method to prepare an efficient electrocatalyst via dealloying of amorphous alloys.展开更多
Due to their excellent properties of specific strength,fracture resistance,corrosion and oxidation resistance,the high-entropy alloys have attracted widespread attention as engineering materials.For the sake of indust...Due to their excellent properties of specific strength,fracture resistance,corrosion and oxidation resistance,the high-entropy alloys have attracted widespread attention as engineering materials.For the sake of industrial applications,one of the essential stages would be the forming of them,especially the construction of multi-sc ale structures from macroscale to nanoscale.展开更多
Metallic glasses(MGs)or amorphous alloys are an important engineering material that has a history of research of about 80–90 years.While different fast cooling methods were developed for multi-component MGs between 1...Metallic glasses(MGs)or amorphous alloys are an important engineering material that has a history of research of about 80–90 years.While different fast cooling methods were developed for multi-component MGs between 1960s and 1980s,1990s witnessed a surge of research interest in the development of bulk metallic glasses(BGMs).Since then,one central theme of research in the metallic-glass community has been compositional design that aims to search for MGs with a better glass forming ability,a larger size and/or more interesting properties,which can hence meet the demands from more important applications.In this review article,we focus on the recent development of chemically complex MGs,such as high entropy MGs,with new tools that were not available or mature yet until recently,such as the state-of-the-art additive manufacturing technologies,high throughput materials design techniques and the methods for big data analyses(e.g.machine learning and artificial intelligence).We also discuss the recent use of MGs in a variety of novel and important applications,from personal healthcare,electric energy transfer to nuclear energy that plays a pivotal role in the battle against global warming.展开更多
To investigate the potential of direct ultrasonic vibration on improving the performance of magnesium alloys,this study first employed the ultrasonic vibration compression(UVC)on the solid solution treated AZ91 alloy,...To investigate the potential of direct ultrasonic vibration on improving the performance of magnesium alloys,this study first employed the ultrasonic vibration compression(UVC)on the solid solution treated AZ91 alloy,and explored its microstructure evolution and mechanical properties under UVC.Within only two seconds,the UVC alloys showed large deformation strains of 34.8–54.4%,and sudden increase of sample temperature to 243℃.Microstructure characterizations proved that UVC promoted the formation of abundant shear bands,fine grains,and the bimodal distribution of Mg17Al12 precipitates consisting of submicron particles located within the shear bands and nano-sized ones within the matrix.Owing to the unique microstructure,the micro-hardness(and nano-hardness)value of UVC alloy was increased by 37.7%(35%)when compared with the solution-treated alloy.Moreover,the nano-modulus of the developed AZ91 alloy was also significantly increased to 62 GPa by statistical nanoindentation tests,which could be ascribed to increased Mg_(17)Al_(12) precipitates and decreased c/a value to some extent.In general,this work provides a new insight into the design and preparation of high-performance magnesium alloys by UVC at room temperature.展开更多
The consumer demand for emerging technologies such as augmented reality(AR),autopilot,and three-dimensional(3D)internet has rapidly promoted the application of novel optical display devices in innovative industries.Ho...The consumer demand for emerging technologies such as augmented reality(AR),autopilot,and three-dimensional(3D)internet has rapidly promoted the application of novel optical display devices in innovative industries.However,the micro/nanomanufacturing of high-resolution optical display devices is the primary issue restricting their development.The manufacturing technology of micro/nanostructures,methods of display mechanisms,display materials,and mass production of display devices are major technical obstacles.To comprehensively understand the latest state-of-the-art and trigger new technological breakthroughs,this study reviews the recent research progress of master molds produced using nanoimprint technology for new optical devices,particularly AR glasses,new-generation light-emitting diode car lighting,and naked-eye 3D display mechanisms,and their manufacturing techniques of master molds.The focus is on the relationships among the manufacturing process,microstructure,and display of a new optical device.Nanoimprint master molds are reviewed for the manufacturing and application of new optical devices,and the challenges and prospects of the new optical device diffraction grating nanoimprint technology are discussed.展开更多
Wear resistance is a critical consideration in engineering applications.In this study,we demonstrated an Ir-Ta-Ni-Nb bulk metallic glass(BMG)with outstanding high-temperature wear resistance and revealed its promising...Wear resistance is a critical consideration in engineering applications.In this study,we demonstrated an Ir-Ta-Ni-Nb bulk metallic glass(BMG)with outstanding high-temperature wear resistance and revealed its promising applications in extreme environments.The wear behavior and mechanism were systemati-cally investigated from room temperature(RT)to 750℃.The results show that the wear rate increases from∼2.65×10^(-6)mm^(3)N^(-1)m^(-1)to∼10.56×10^(-6)mm^(3)N^(-1)m^(-1)in the temperature span RT to 400℃,following abrasive wear and flash temperature-induced oxidative wear during the friction.However,at the higher temperature of 600℃,further heating due to frictional heat leads to a softening of the wear surface,resulting in a maximum wear rate of∼20.99×10^(-6)mm^(3)N^(-1)m^(-1)under softness-driven abrasive wear as well as oxidative wear.Interestingly,the wear resistance at an even higher temperature of 750℃shows a paradoxical improvement of∼7.08×10^(-6)mm^(3)N^(-1)m^(-1),which is attributed to the formation of an oxide layer with a thickness of several microns,avoiding violent wear of BMG.The re-sults demonstrate the unreported outstanding high-temperature wear resistance of the Ir-Ta-Ni-Nb BMG,especially its excellent capability to resist wear at 750℃,leading to the promising applications of BMG in the fields of aerospace,metallurgy,and nuclear industries.展开更多
Metallic glasses(MGs)possess exceptional properties,but their properties consistently deteriorate over time,thereby resulting in increased complexity in processing.It thus poses a formidable challenge to the forming o...Metallic glasses(MGs)possess exceptional properties,but their properties consistently deteriorate over time,thereby resulting in increased complexity in processing.It thus poses a formidable challenge to the forming of long-term aged MGs.Here,we report ultrasonic vibration(UV)loading can lead to large plas-ticity and strong rejuvenation in significantly aged MGs within 1 s.A large UV-induced plasticity(UVIP)of 80%height reduction can be achieved in LaNiAl MG samples aged at 85%of its glass transition tem-perature(0.85 T_(g))for a duration of up to 1 month.The energy threshold required for UVIP monotonously increases with aging time.After the UV loading process,the aged samples show strong rejuvenation,with the relaxation enthalpy even surpassing that of as-cast samples.These findings suggest that UV loading is an effective technique for forming and rejuvenating aged MGs simultaneously,providing an alterna-tive avenue to explore the interplay between the property and microstructures as well as expanding the application prospects of MGs.展开更多
Torque sensors are essential components of robotic joints. In the past, structure optimization of force-sensing elements has been the common approach to improve the performance of the torque sensors. In this work, we ...Torque sensors are essential components of robotic joints. In the past, structure optimization of force-sensing elements has been the common approach to improve the performance of the torque sensors. In this work, we demonstrate a torque sensor with bulk metallic glasses as a force-sensing element. Compared with the sensors made of stainless steel and aluminum alloy, the use of bulk metallic glass as a force-sensing element significantly improves sensor sensitivity, linearity, repeatability, hysteresis, and measuring range. Our work not only opens up a new avenue for the application of bulk metallic glasses, but also provides opportunities for enhancing the performance of force/torque sensors through materials optimization.展开更多
Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of MGs.However,whether all ...Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of MGs.However,whether all MGs possessing UVIP remains a mystery.展开更多
Glass-forming ability is a long-standing concern in the field of metallic glasses(MGs),which greatly limits their maximum casting size and extensive applications.In this work,we report an ultrasonic-assisted rapid col...Glass-forming ability is a long-standing concern in the field of metallic glasses(MGs),which greatly limits their maximum casting size and extensive applications.In this work,we report an ultrasonic-assisted rapid cold welding of bulk MGs without using any additives.MGs with various compositions are welded together under a 20,000-Hz highfrequency ultrasonic vibration without losing their amorphous nature.The ultrasonic technology offers the advantages of rapid bonding(<1 s)at low temperature(near room temperature)and low stress(<1 MPa).According to the phenomenon observed in the experiment,the activated fresh atoms diffuse through the broken channel port under continuous rupture of the oxide layer,and the ultrasonic vibration accelerates the atomic-diffusion process.Finally,stable bonding of the MG interface is realized.This universal ultrasonic-assisted welding process can realize the composition design of dissimilar MGs as well as tuning of new materials with new performance.展开更多
Microstructural functional surfaces play an important role in energy conversion applications including power generation,air conditioning,and thermal management of electronics through the boiling process.In this study,...Microstructural functional surfaces play an important role in energy conversion applications including power generation,air conditioning,and thermal management of electronics through the boiling process.In this study,multi-scale microgroove surfaces were fabricated by the combination of wire electrical discharge machining(WEDM)and electrical discharge shaped machining(EDSM)to achieve a better boiling performance.The WEDM,with the advantage of high efficiency,was used to fabricate the first microgroove array,and rougher surfaces were formed by intense discharge.A wavy electrode was used in EDSM to fabricate the second microgroove array.Reentrant cavities at the intersections of microgrooves and rougher micro fins with spacing distribution were formed after EDSM.The boiling performance of the multi-scale microgroove surface was studied with water as the working medium under atmospheric pressure.The results indicated that the boiling performance of the microgroove surface is significantly enhanced.The critical heat flux and maximum heat transfer coefficient of microgroove surface were higher than the surfaces fabricated only by WEDM or EDSM,which were 2.34 and 3.29 times that of smooth copper plate,respectively.This study demonstrated that the combination of WEDM and EDSM is a convenient and effective method to fabricate high-performance microgroove boiling surfaces.展开更多
A facile,precise,and controllable manufacturing technology is desired for hierarchical functional surfaces.In this work,we successfully manufactured porous metallic glass using a water-dissolution material as template...A facile,precise,and controllable manufacturing technology is desired for hierarchical functional surfaces.In this work,we successfully manufactured porous metallic glass using a water-dissolution material as template and the excellent thermoplastic property of metallic glass.The prepared micro/nanostructures have excellent tunability,and the proposed approach can be used to prepare large-area disordered porous structures and ordered regular arrays with nanoscale replication accuracy.In particular,the disordered porous structure prepared by the dissolvable template strategy exhibits a water contact angle of~140°and an oil contact angle of~0°,making it suitable for oil/water separation.It also shows stable wettability after being soaked in strong acid or alkali environments and maintains a~130°water contact angle and a~4°oil contact angle even after severe wear.The proposed strategy also possesses excellent recycling properties.We reconstructed porous structures on the same surface three times and found no significant change in wettability for each reconstructed porous structure.Our research provides a facile and controllable approach for the preparation of hierarchical porous structures and paves the way for the design of other functional surfaces.展开更多
The design of metallic materials with high strength,high ductility,and high thermal stability has always been a long-sought goal for the materials science community.However,the trade-off between strength and ductility...The design of metallic materials with high strength,high ductility,and high thermal stability has always been a long-sought goal for the materials science community.However,the trade-off between strength and ductility remains a challenge.Here,we proposed a new strategy to design and fabricate bulk amorphous-crystalline dual-phase superior alloys out of the Al_(80)Li_(5)Mg_(5)Zn_(5)Cu_(5)multicomponent alloy.The nano-amorphous phase revealed unexpected thermal stability during fabrication and mechanical testing above the crystallization temperature.The true fracture strength of the Al_(80)Li_(5)Mg_(5)Zn_(5)Cu_(5)nano-amorphous-crystal dual-phase multicomponent alloy was increased from 528 to 657 MPa,and the true strain was increased from 18%to 48%.In addition,the alloy yielded a strength 1.5 times higher than that of the commonly used high-strength aluminum alloys at 250℃.This strategy provided a new approach and concept for the design of high-performance alloys to ensure strength-plasticity balance.展开更多
Broadband light absorption is important for applications such as infrared detectors,solar energy collectors,and photothermal conversion.We propose a facile and common strategy to fabricate light absorbers with strong ...Broadband light absorption is important for applications such as infrared detectors,solar energy collectors,and photothermal conversion.We propose a facile and common strategy to fabricate light absorbers with strong ultra-wideband absorption.Due to their excellent thermoplastic forming ability,metallic glasses could be patterned into finely arranged nanowire arrays,which show extremely low reflectivity(∼0.6%)in the visible and near-infrared regimes,and a low reflectivity(∼15%)in the mid-infrared regime as caused by multiscale nano spacing,multiple reflections,and plasmonic behavior.The strong absorption at surfaces with nanowires provides excellent photothermal conversion properties.The photothermal properties show that a surface with nanowires can be rapidly heated up to∼160°C at a rate of 28.75°C/s,which is 30 times higher than smooth surfaces.Meanwhile,a surface with nanowires shows a high photothermal conversion efficiency(η_(PT)=56.36%).The fabricated metallic glass absorbers exhibit adaptability as they can be easily formed into various complex shapes and meet the requirements under harsh conditions.The outcomes of our research open the door to manufacturing high-performance absorbers for applications in photothermal electric power generation,desalination,and photodetectors.展开更多
This brief review reports the recent advancement of metallic glasses and metallic glass nanostructures for functional electrocatalytic applications. Metallic glasses(MGs) or amorphous metals result from quenching the ...This brief review reports the recent advancement of metallic glasses and metallic glass nanostructures for functional electrocatalytic applications. Metallic glasses(MGs) or amorphous metals result from quenching the melts at a high cooling rate(e.g.,10^(6)K/s), bypassing crystallization. Metallic glasses are devoid of long-range translational order, no defects like grain boundaries, and multiple elements included. Due to these unique structural features, MG s show distinct and valuable mechanical, physical and chemical properties and therefore were widely studied as a structural material for decades. Even though MGs were proposed for catalytic applications earlier, a comprehensive study or attempt to apply these materials successfully in electrocatalytic applications are few since the intrinsic surface area is comparably lesser. A rejuvenated interest among the research community for applying various novel strategies in catalytic applications of MGs is highlighted in the present review. Theoretical approaches using density functional theory(DFT) and high-throughput screening assisted with machine learning paradigm advances the discovery of new MGs, which demonstrated high potential for catalytic applications. We focus on the basic features and recent advances in the MGs for catalytic applications like electrocatalytic water splitting reactions like HER, OER, fuel cell reactions like ORR, alcohol oxidation reactions like MOR, EOR,and degradation of harmful organic dyes from the industrial effluents. The presently advancing strategies for enhancing the performance of these metallic glass electrocatalysts through nanostructuring and high-throughput screening are discussed. The unique atomic-scale structural mechanism of the metallic glasses, which can favor the development of high-performance electrocatalysts even comparable to currently available precious-metal-based catalysts, will be discussed. Finally, we also give future directions on designing novel and superior metallic glass-based advanced catalysts.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:52071217。
文摘Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was performed to prepare a freestanding nanostructured hydrogen evolution reaction(HER)catalyst.The effect of dealloying and addition of Ru to TiCu alloys on the microstructure and HER properties under alkaline conditions was investigated.3 at.%Ru addition in Ti_(40)Cu_(60) decreases the overpotential to reach a current density of 10mA cm^(-2) and Tafel slope of the dealloyed samples to 35 and 34mV dec−1.The improvement of electrocatalytic properties was attributed to the formation of a nanostructure and the modification of the electronic structure of the catalyst.First-principles calculations based on density function theory indicate that Ru decreases the Gibbs free energy of water dissociation.This work presents a method to prepare an efficient electrocatalyst via dealloying of amorphous alloys.
基金financially supported by the National Key Research and Development Program of China(Nos.2018YFA0703605)the Key Basic and Applied Research Program of Guangdong Province,China(No.2019B030302010)the National Natural Science Foundation of China(Nos.52122105,51971150 and 51871157)。
文摘Due to their excellent properties of specific strength,fracture resistance,corrosion and oxidation resistance,the high-entropy alloys have attracted widespread attention as engineering materials.For the sake of industrial applications,one of the essential stages would be the forming of them,especially the construction of multi-sc ale structures from macroscale to nanoscale.
基金Y Y acknowledges financial support provided by the Research Grants Committee(RGC),the Hong Kong government,the General Research Fund(GRF)with Grant Nos.CityU11200719 and CityU11213118also by the City University of Hong Kong through an internal grant with Grant No.7005438.
文摘Metallic glasses(MGs)or amorphous alloys are an important engineering material that has a history of research of about 80–90 years.While different fast cooling methods were developed for multi-component MGs between 1960s and 1980s,1990s witnessed a surge of research interest in the development of bulk metallic glasses(BGMs).Since then,one central theme of research in the metallic-glass community has been compositional design that aims to search for MGs with a better glass forming ability,a larger size and/or more interesting properties,which can hence meet the demands from more important applications.In this review article,we focus on the recent development of chemically complex MGs,such as high entropy MGs,with new tools that were not available or mature yet until recently,such as the state-of-the-art additive manufacturing technologies,high throughput materials design techniques and the methods for big data analyses(e.g.machine learning and artificial intelligence).We also discuss the recent use of MGs in a variety of novel and important applications,from personal healthcare,electric energy transfer to nuclear energy that plays a pivotal role in the battle against global warming.
基金supported by the National Natural Science Foundation of China(Nos.52271101,51901068)the Project on Excellent Post-graduate Dissertation of Hohai University(No.422003518)+3 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_0175)the Key Research and Development Program of Jiangsu Province(No.BE2021027)the Suzhou Science and Technology Project(Nos.SYG202312,SJC2023005,SZS2023023)the Nanjing Major Science and Technology Project(No.202309015).
文摘To investigate the potential of direct ultrasonic vibration on improving the performance of magnesium alloys,this study first employed the ultrasonic vibration compression(UVC)on the solid solution treated AZ91 alloy,and explored its microstructure evolution and mechanical properties under UVC.Within only two seconds,the UVC alloys showed large deformation strains of 34.8–54.4%,and sudden increase of sample temperature to 243℃.Microstructure characterizations proved that UVC promoted the formation of abundant shear bands,fine grains,and the bimodal distribution of Mg17Al12 precipitates consisting of submicron particles located within the shear bands and nano-sized ones within the matrix.Owing to the unique microstructure,the micro-hardness(and nano-hardness)value of UVC alloy was increased by 37.7%(35%)when compared with the solution-treated alloy.Moreover,the nano-modulus of the developed AZ91 alloy was also significantly increased to 62 GPa by statistical nanoindentation tests,which could be ascribed to increased Mg_(17)Al_(12) precipitates and decreased c/a value to some extent.In general,this work provides a new insight into the design and preparation of high-performance magnesium alloys by UVC at room temperature.
基金supported by the Fundamental Key Research Project of Shenzhen(Grant No.JCYJ20210324115806017)the Innovation and Entrepreneurship Project for Overseas High-Level Talents of Shenzhen(Grant No.KQJSCX20180328095603847)+1 种基金the National Natural Science Foundation of China(Grant No.51805331)the National Key R&D Program of China(Grant No.6142005180401).
文摘The consumer demand for emerging technologies such as augmented reality(AR),autopilot,and three-dimensional(3D)internet has rapidly promoted the application of novel optical display devices in innovative industries.However,the micro/nanomanufacturing of high-resolution optical display devices is the primary issue restricting their development.The manufacturing technology of micro/nanostructures,methods of display mechanisms,display materials,and mass production of display devices are major technical obstacles.To comprehensively understand the latest state-of-the-art and trigger new technological breakthroughs,this study reviews the recent research progress of master molds produced using nanoimprint technology for new optical devices,particularly AR glasses,new-generation light-emitting diode car lighting,and naked-eye 3D display mechanisms,and their manufacturing techniques of master molds.The focus is on the relationships among the manufacturing process,microstructure,and display of a new optical device.Nanoimprint master molds are reviewed for the manufacturing and application of new optical devices,and the challenges and prospects of the new optical device diffraction grating nanoimprint technology are discussed.
基金financially supported by the National Key Research and Development Program of China(Grant No.2018YFA0703605)the Key Basic and Applied Research Pro-gram of Guangdong Province,China(Grant No.2019B030302010)+1 种基金the NSF of China(Grant No.52122105,51971150)the Science and Technology Innovation Commission Shenzhen(Grants No.RCJC20221008092730037,20220804091920001)。
文摘Wear resistance is a critical consideration in engineering applications.In this study,we demonstrated an Ir-Ta-Ni-Nb bulk metallic glass(BMG)with outstanding high-temperature wear resistance and revealed its promising applications in extreme environments.The wear behavior and mechanism were systemati-cally investigated from room temperature(RT)to 750℃.The results show that the wear rate increases from∼2.65×10^(-6)mm^(3)N^(-1)m^(-1)to∼10.56×10^(-6)mm^(3)N^(-1)m^(-1)in the temperature span RT to 400℃,following abrasive wear and flash temperature-induced oxidative wear during the friction.However,at the higher temperature of 600℃,further heating due to frictional heat leads to a softening of the wear surface,resulting in a maximum wear rate of∼20.99×10^(-6)mm^(3)N^(-1)m^(-1)under softness-driven abrasive wear as well as oxidative wear.Interestingly,the wear resistance at an even higher temperature of 750℃shows a paradoxical improvement of∼7.08×10^(-6)mm^(3)N^(-1)m^(-1),which is attributed to the formation of an oxide layer with a thickness of several microns,avoiding violent wear of BMG.The re-sults demonstrate the unreported outstanding high-temperature wear resistance of the Ir-Ta-Ni-Nb BMG,especially its excellent capability to resist wear at 750℃,leading to the promising applications of BMG in the fields of aerospace,metallurgy,and nuclear industries.
基金supported by the Key Basic and Applied Research Program of Guangdong Province,China(Grant No.2019B030302010)the NSF of China(Grant Nos.52122105,51971150,51901243)+1 种基金the Science and Technology Innovation Commission Shenzhen(Grants No.RCJC20221008092730037 and 20220804091920001)the National Key Research and Development Program of China(Grant No.2018YFA0703605).
文摘Metallic glasses(MGs)possess exceptional properties,but their properties consistently deteriorate over time,thereby resulting in increased complexity in processing.It thus poses a formidable challenge to the forming of long-term aged MGs.Here,we report ultrasonic vibration(UV)loading can lead to large plas-ticity and strong rejuvenation in significantly aged MGs within 1 s.A large UV-induced plasticity(UVIP)of 80%height reduction can be achieved in LaNiAl MG samples aged at 85%of its glass transition tem-perature(0.85 T_(g))for a duration of up to 1 month.The energy threshold required for UVIP monotonously increases with aging time.After the UV loading process,the aged samples show strong rejuvenation,with the relaxation enthalpy even surpassing that of as-cast samples.These findings suggest that UV loading is an effective technique for forming and rejuvenating aged MGs simultaneously,providing an alterna-tive avenue to explore the interplay between the property and microstructures as well as expanding the application prospects of MGs.
基金supported by the National Natural Science Foundation of China (Grant No. 51825104)the National Key Research and Development Program of China (Grant No. 2018YFA0703600)。
文摘Torque sensors are essential components of robotic joints. In the past, structure optimization of force-sensing elements has been the common approach to improve the performance of the torque sensors. In this work, we demonstrate a torque sensor with bulk metallic glasses as a force-sensing element. Compared with the sensors made of stainless steel and aluminum alloy, the use of bulk metallic glass as a force-sensing element significantly improves sensor sensitivity, linearity, repeatability, hysteresis, and measuring range. Our work not only opens up a new avenue for the application of bulk metallic glasses, but also provides opportunities for enhancing the performance of force/torque sensors through materials optimization.
基金financially supported by the Key Basic and Applied Research Program of Guangdong Province, China (No.2019B030302010)the National Natural Science Foundation of China (Nos.52371160,51901243,52122105 and 51971150)the National Key Research and Development Program of China (No.2018YFA0703604)。
文摘Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of MGs.However,whether all MGs possessing UVIP remains a mystery.
基金supported by the Key Basic and Applied Research Program of Guangdong Province,China(2019B030302010)the National Natural Science Foundation of China(51871157,51971150 and 51775351)+2 种基金the Science and Technology Innovation Commission Shenzhen(JCYJ20170412111216258)the National Key Research and Development Program of China(2018YFA0703605)Shenzhen Basic Research Project(JCYJ20190808152409578).
文摘Glass-forming ability is a long-standing concern in the field of metallic glasses(MGs),which greatly limits their maximum casting size and extensive applications.In this work,we report an ultrasonic-assisted rapid cold welding of bulk MGs without using any additives.MGs with various compositions are welded together under a 20,000-Hz highfrequency ultrasonic vibration without losing their amorphous nature.The ultrasonic technology offers the advantages of rapid bonding(<1 s)at low temperature(near room temperature)and low stress(<1 MPa).According to the phenomenon observed in the experiment,the activated fresh atoms diffuse through the broken channel port under continuous rupture of the oxide layer,and the ultrasonic vibration accelerates the atomic-diffusion process.Finally,stable bonding of the MG interface is realized.This universal ultrasonic-assisted welding process can realize the composition design of dissimilar MGs as well as tuning of new materials with new performance.
基金supported by the National Natural Science Foundation of China(Grant No.51905352)the Natural Science Foundation of Guangdong Province(Grant No.2020A1515011039)+1 种基金the Excellent Science and Technology Creative Talent Training Program of Shenzhen(Grant No.RCBS20210609103819021)the Basic Research Foundation of Shenzhen(Grant No.JCYJ20190808144003701)。
文摘Microstructural functional surfaces play an important role in energy conversion applications including power generation,air conditioning,and thermal management of electronics through the boiling process.In this study,multi-scale microgroove surfaces were fabricated by the combination of wire electrical discharge machining(WEDM)and electrical discharge shaped machining(EDSM)to achieve a better boiling performance.The WEDM,with the advantage of high efficiency,was used to fabricate the first microgroove array,and rougher surfaces were formed by intense discharge.A wavy electrode was used in EDSM to fabricate the second microgroove array.Reentrant cavities at the intersections of microgrooves and rougher micro fins with spacing distribution were formed after EDSM.The boiling performance of the multi-scale microgroove surface was studied with water as the working medium under atmospheric pressure.The results indicated that the boiling performance of the microgroove surface is significantly enhanced.The critical heat flux and maximum heat transfer coefficient of microgroove surface were higher than the surfaces fabricated only by WEDM or EDSM,which were 2.34 and 3.29 times that of smooth copper plate,respectively.This study demonstrated that the combination of WEDM and EDSM is a convenient and effective method to fabricate high-performance microgroove boiling surfaces.
基金supported by the Key Basic and Applied Research Program of Guangdong Province,China(2019B030302010)the National Natural Science Foundation of China(52122105,51871157,and 51971150)the National Key Research and Development Program of China(2018YFA0703604)。
文摘A facile,precise,and controllable manufacturing technology is desired for hierarchical functional surfaces.In this work,we successfully manufactured porous metallic glass using a water-dissolution material as template and the excellent thermoplastic property of metallic glass.The prepared micro/nanostructures have excellent tunability,and the proposed approach can be used to prepare large-area disordered porous structures and ordered regular arrays with nanoscale replication accuracy.In particular,the disordered porous structure prepared by the dissolvable template strategy exhibits a water contact angle of~140°and an oil contact angle of~0°,making it suitable for oil/water separation.It also shows stable wettability after being soaked in strong acid or alkali environments and maintains a~130°water contact angle and a~4°oil contact angle even after severe wear.The proposed strategy also possesses excellent recycling properties.We reconstructed porous structures on the same surface three times and found no significant change in wettability for each reconstructed porous structure.Our research provides a facile and controllable approach for the preparation of hierarchical porous structures and paves the way for the design of other functional surfaces.
基金supported by the Key Basic and Applied Research Program of Guangdong Province, China (2019B030302010)the National Natural Science Foundation of China (52122105 and 51871157)the National Key Research and Development Program of China (2018YFA0703604)
文摘The design of metallic materials with high strength,high ductility,and high thermal stability has always been a long-sought goal for the materials science community.However,the trade-off between strength and ductility remains a challenge.Here,we proposed a new strategy to design and fabricate bulk amorphous-crystalline dual-phase superior alloys out of the Al_(80)Li_(5)Mg_(5)Zn_(5)Cu_(5)multicomponent alloy.The nano-amorphous phase revealed unexpected thermal stability during fabrication and mechanical testing above the crystallization temperature.The true fracture strength of the Al_(80)Li_(5)Mg_(5)Zn_(5)Cu_(5)nano-amorphous-crystal dual-phase multicomponent alloy was increased from 528 to 657 MPa,and the true strain was increased from 18%to 48%.In addition,the alloy yielded a strength 1.5 times higher than that of the commonly used high-strength aluminum alloys at 250℃.This strategy provided a new approach and concept for the design of high-performance alloys to ensure strength-plasticity balance.
基金supported by the Key Basic and Applied Research Program of Guangdong Province,China(2019B030302010)the National Natural Science Foundation of China(51871157,and 51971150)the National Key Research and Development Program of China(2018YFA0703604).
文摘Broadband light absorption is important for applications such as infrared detectors,solar energy collectors,and photothermal conversion.We propose a facile and common strategy to fabricate light absorbers with strong ultra-wideband absorption.Due to their excellent thermoplastic forming ability,metallic glasses could be patterned into finely arranged nanowire arrays,which show extremely low reflectivity(∼0.6%)in the visible and near-infrared regimes,and a low reflectivity(∼15%)in the mid-infrared regime as caused by multiscale nano spacing,multiple reflections,and plasmonic behavior.The strong absorption at surfaces with nanowires provides excellent photothermal conversion properties.The photothermal properties show that a surface with nanowires can be rapidly heated up to∼160°C at a rate of 28.75°C/s,which is 30 times higher than smooth surfaces.Meanwhile,a surface with nanowires shows a high photothermal conversion efficiency(η_(PT)=56.36%).The fabricated metallic glass absorbers exhibit adaptability as they can be easily formed into various complex shapes and meet the requirements under harsh conditions.The outcomes of our research open the door to manufacturing high-performance absorbers for applications in photothermal electric power generation,desalination,and photodetectors.
基金supported by the China National Natural Science Foundation(No.52071217).
文摘This brief review reports the recent advancement of metallic glasses and metallic glass nanostructures for functional electrocatalytic applications. Metallic glasses(MGs) or amorphous metals result from quenching the melts at a high cooling rate(e.g.,10^(6)K/s), bypassing crystallization. Metallic glasses are devoid of long-range translational order, no defects like grain boundaries, and multiple elements included. Due to these unique structural features, MG s show distinct and valuable mechanical, physical and chemical properties and therefore were widely studied as a structural material for decades. Even though MGs were proposed for catalytic applications earlier, a comprehensive study or attempt to apply these materials successfully in electrocatalytic applications are few since the intrinsic surface area is comparably lesser. A rejuvenated interest among the research community for applying various novel strategies in catalytic applications of MGs is highlighted in the present review. Theoretical approaches using density functional theory(DFT) and high-throughput screening assisted with machine learning paradigm advances the discovery of new MGs, which demonstrated high potential for catalytic applications. We focus on the basic features and recent advances in the MGs for catalytic applications like electrocatalytic water splitting reactions like HER, OER, fuel cell reactions like ORR, alcohol oxidation reactions like MOR, EOR,and degradation of harmful organic dyes from the industrial effluents. The presently advancing strategies for enhancing the performance of these metallic glass electrocatalysts through nanostructuring and high-throughput screening are discussed. The unique atomic-scale structural mechanism of the metallic glasses, which can favor the development of high-performance electrocatalysts even comparable to currently available precious-metal-based catalysts, will be discussed. Finally, we also give future directions on designing novel and superior metallic glass-based advanced catalysts.
