Conventional intermetallics are strong but brit-tle.However,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,s...Conventional intermetallics are strong but brit-tle.However,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,some of which even show appreciable ductility and fracture toughness at room temperature.In this article,we provide a focused review on the recent researches on HEIs,from the fundamentals,such as the concept of HEIs,the formation rules to the structural and functional properties of HEIs.The results hitherto reported clearly show that the HEIs with distinct properties could be a promising material for future structural and functional applications.展开更多
The compositional design of metallic glasses(MGs)is a long-standing issue in materials science and engineering.However,traditional experimental approaches based on empirical rules are time consuming with a low efficie...The compositional design of metallic glasses(MGs)is a long-standing issue in materials science and engineering.However,traditional experimental approaches based on empirical rules are time consuming with a low efficiency.In this work,we successfully developed a hybrid machine learning(ML)model to address this fundamental issue based on a database containing~5000 different compositions of metallic glasses(either bulk or ribbon)reported since 1960s.Unlike the prior works relying on empirical parameters for featurization of data,we designed modeling guided data descriptors in line with the recent theoretical models on amorphization in chemically complex alloys for the development of the hybrid classification-regression ML algorithms.Our hybrid ML modeling was validated both numerically and experimentally.Most importantly,it enabled the discovery of MGs(either bulk or ribbon)through the ML-aided deep search of a multitude of quaternary to scenery alloy compositions.The computational framework herein established is expected to accelerate the design of MG compositions and expand their applications by probing the complex and multi-dimensional compositional space that has never been explored before.展开更多
The design of bulk metallic glasses(BMGs)via machine learning(ML)has been a topic of active research recently.However,the prior ML models were mostly built upon supervised learning algorithms with human inputs to navi...The design of bulk metallic glasses(BMGs)via machine learning(ML)has been a topic of active research recently.However,the prior ML models were mostly built upon supervised learning algorithms with human inputs to navigate the high dimensional compositional space,which becomes inefficient with the increasing compositional complexity in BMGs.Here,we develop a generative deep-learning framework to directly generate compositionally complex BMGs,such as high entropy BMGs.Our framework is built on the unsupervised Generative Adversarial Network(GAN)algorithm for data generation and the supervised Boosted Trees algorithm for data evaluation.We studied systematically the confounding effect of various data descriptors and the literature data on the effectiveness of our framework both numerically and experimentally.Most importantly,we demonstrate that our generative deep learning framework is capable of producing composition-property mappings,therefore paving the way for the inverse design of BMGs.展开更多
High corrosion resistance of alloys is essential for their structural applications;however,most alloys suffer from degradation of their corrosion resistance with the increasing acidity of their surround-ings.Nonethele...High corrosion resistance of alloys is essential for their structural applications;however,most alloys suffer from degradation of their corrosion resistance with the increasing acidity of their surround-ings.Nonetheless,we developed a series of medium-entropy alloys(MEAs)in this work,which ex-hibit high strength,superior fracture toughness and ultra-high corrosion resistance,outperforming the variety of corrosion resistant alloys hitherto reported.Most interestingly,our MEAs exhibit an unusual anti-corrosion behavior and their corrosion resistance increases with acidity in Cl−containing solutions.Through extensive thermodynamic calculations,density functional theory(DFT)simulations and experi-ments,we reveal that the unusual anti-corrosion behavior of our MEAs can be attributed to their surface chemical complexity,which facilitates the physio-chemical-absorption of H_(2)O and O_(2)and thus the rapid formation of metastable medium entropy passive films that contain the lowest amount of defects,as compared to the passive films on conventional alloys reported in the literature.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
Glasses have long been considered as frozen liquids because of the similarity between their static amorphous structures.While the modern theories about glass transition suggest that glass transition may result from su...Glasses have long been considered as frozen liquids because of the similarity between their static amorphous structures.While the modern theories about glass transition suggest that glass transition may result from supercooling of a heterogeneous liquid that contains fast and slow regions,it remains unclear whether such a physical picture applies to metallic glasses,which are a densely packed solid glass that was once believed to be a vitrified homogeneous metallic liquid.However,in the recent work published in Nature Materials,Chang et al provide compelling evidence to show that metallic glasses contain liquid-like atoms that behave as a high-temperature liquid in stress relaxation.Being activated under cyclic loading,this quenched-in liquid results in a fast relaxation process,which is discovered in a variety of metallic glasses.Their results are important and deliver a strong message that metallic glasses have a dynamic microstructure containing liquid-and solid-like atoms.Most importantly,the outcome of their research provides physical insight into the nature of glass-transition in metallic glasses,and also helps unravel their structure-property relations.展开更多
基金financially supported by the General Research Fund (GRF) from Research Grant Council,the Hong Kong Government (Nos.CityU11213118 and CityU11200719)the fund from City University of Hong Kong (No.7005438)
文摘Conventional intermetallics are strong but brit-tle.However,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,some of which even show appreciable ductility and fracture toughness at room temperature.In this article,we provide a focused review on the recent researches on HEIs,from the fundamentals,such as the concept of HEIs,the formation rules to the structural and functional properties of HEIs.The results hitherto reported clearly show that the HEIs with distinct properties could be a promising material for future structural and functional applications.
基金The research of YY is supported by the Research Grant Council,the Hong Kong Government,through the General Research Fund(GRF)with the grant numbers CityU11209317,CityU11213118,and CityU11200719Atom probe tomography research was conducted by Dr.JH LUAN at the Inter-University 3D Atom Probe Tomography Unit of City University of Hong Kong,which is supported by the CityU grant 9360161。
文摘The compositional design of metallic glasses(MGs)is a long-standing issue in materials science and engineering.However,traditional experimental approaches based on empirical rules are time consuming with a low efficiency.In this work,we successfully developed a hybrid machine learning(ML)model to address this fundamental issue based on a database containing~5000 different compositions of metallic glasses(either bulk or ribbon)reported since 1960s.Unlike the prior works relying on empirical parameters for featurization of data,we designed modeling guided data descriptors in line with the recent theoretical models on amorphization in chemically complex alloys for the development of the hybrid classification-regression ML algorithms.Our hybrid ML modeling was validated both numerically and experimentally.Most importantly,it enabled the discovery of MGs(either bulk or ribbon)through the ML-aided deep search of a multitude of quaternary to scenery alloy compositions.The computational framework herein established is expected to accelerate the design of MG compositions and expand their applications by probing the complex and multi-dimensional compositional space that has never been explored before.
基金The research of Y.Y.is supported by the research grant Council(RGC),the Hong Kong government,through the general research fund(GRF)with the grant numbers of N_CityU 109/21,CityU11200719 and CityU11213118.
文摘The design of bulk metallic glasses(BMGs)via machine learning(ML)has been a topic of active research recently.However,the prior ML models were mostly built upon supervised learning algorithms with human inputs to navigate the high dimensional compositional space,which becomes inefficient with the increasing compositional complexity in BMGs.Here,we develop a generative deep-learning framework to directly generate compositionally complex BMGs,such as high entropy BMGs.Our framework is built on the unsupervised Generative Adversarial Network(GAN)algorithm for data generation and the supervised Boosted Trees algorithm for data evaluation.We studied systematically the confounding effect of various data descriptors and the literature data on the effectiveness of our framework both numerically and experimentally.Most importantly,we demonstrate that our generative deep learning framework is capable of producing composition-property mappings,therefore paving the way for the inverse design of BMGs.
基金Y.Yang was supported by Research Grant Council(RGC),Hong Kong Government,through General Research Fund(RGC)(Nos.CityU11213118,CityU11200719 and CityU11209317).
文摘High corrosion resistance of alloys is essential for their structural applications;however,most alloys suffer from degradation of their corrosion resistance with the increasing acidity of their surround-ings.Nonetheless,we developed a series of medium-entropy alloys(MEAs)in this work,which ex-hibit high strength,superior fracture toughness and ultra-high corrosion resistance,outperforming the variety of corrosion resistant alloys hitherto reported.Most interestingly,our MEAs exhibit an unusual anti-corrosion behavior and their corrosion resistance increases with acidity in Cl−containing solutions.Through extensive thermodynamic calculations,density functional theory(DFT)simulations and experi-ments,we reveal that the unusual anti-corrosion behavior of our MEAs can be attributed to their surface chemical complexity,which facilitates the physio-chemical-absorption of H_(2)O and O_(2)and thus the rapid formation of metastable medium entropy passive films that contain the lowest amount of defects,as compared to the passive films on conventional alloys reported in the literature.
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the financial support provided by Research Grants Council,the Hong Kong government through the General Research Fund(Grant Nos.CityU11200719 and CityU11213118)the City University of Hong Kong through CityU Strategic Research Grant(Grant No.7005438)+1 种基金Q W acknowledges the financial support provided by Natural Science Foundation of China(Grant Nos.52171161,51871140)the space utilization system of China Manned Space Engineering(KJZ-YY-NCL08).
文摘Glasses have long been considered as frozen liquids because of the similarity between their static amorphous structures.While the modern theories about glass transition suggest that glass transition may result from supercooling of a heterogeneous liquid that contains fast and slow regions,it remains unclear whether such a physical picture applies to metallic glasses,which are a densely packed solid glass that was once believed to be a vitrified homogeneous metallic liquid.However,in the recent work published in Nature Materials,Chang et al provide compelling evidence to show that metallic glasses contain liquid-like atoms that behave as a high-temperature liquid in stress relaxation.Being activated under cyclic loading,this quenched-in liquid results in a fast relaxation process,which is discovered in a variety of metallic glasses.Their results are important and deliver a strong message that metallic glasses have a dynamic microstructure containing liquid-and solid-like atoms.Most importantly,the outcome of their research provides physical insight into the nature of glass-transition in metallic glasses,and also helps unravel their structure-property relations.
