High-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous researchers.Entropy,in this context,can be perceived as representing disorder and randomness...High-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous researchers.Entropy,in this context,can be perceived as representing disorder and randomness.By contrast,elemental composi-tions within alloy systems occupy specific structural sites in space,a concept referred to as structure.In accordance with Shannon entropy,structure is analogous to information.Generally,the arrangement of atoms within a material,termed its structure,plays a pivotal role in dictating its properties.In addition to expanding the array of options for alloy composites,HEAs afford ample opportunities for diverse structural designs.The profound influence of distinct structural features on the exceptional behaviors of alloys is underscored by numer-ous examples.These features include remarkably high fracture strength with excellent ductility,antiballistic capability,exceptional radi-ation resistance,and corrosion resistance.In this paper,we delve into various unique material structures and properties while elucidating the intricate relationship between structure and performance.展开更多
In order to improve the application values of Ce element, in this paper, rare earth chloride solution was used as raw material, the pH value was controlled by inorganic alkali, the ceria powders with special physical ...In order to improve the application values of Ce element, in this paper, rare earth chloride solution was used as raw material, the pH value was controlled by inorganic alkali, the ceria powders with special physical properties were prepared by carbon dioxide carbonization method. According to characterization of SEM, XRD, and TG-DSC, Ce（OH）3 prepared at pH = 7.5 exhibits smaller particle size than that prepared at other conditions. CeO2 precursor obtained by direct carbonization of Ce（OH）3 shows smaller particle size and narrow size distribution, CeO2 precursor forms at first by carbonization of Ce（OH）3 with the continuous addition of CO2 gas,and the chemical component is indicated to be Ce2 O（CO3）2·6 H2 O.Cubic phase CeO2 powders are obtained by calcined at 750 ℃ for 4 h. The mean particle size D（50） is0.941 μm, and particle size distribution is smaller than 1. The microscopic appearance is homogeneous,with a spherical-like shape and a grain size of 200-500 nm. The light quality characteristics of sedimentation volume and accumulation density are obviously better than those of carbonate precipitation products. The carbonization method can be used not only to obtain ultra-fine rare earth oxides with fine particle size, narrow distribution and high dispersion properties, but also to achieve the reuse of carbon dioxide greenhouse gas.展开更多
基金supported by the National Natural Science Foundation of China(No.52273280)the Creative Research Groups of China(No.51921001).
文摘High-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous researchers.Entropy,in this context,can be perceived as representing disorder and randomness.By contrast,elemental composi-tions within alloy systems occupy specific structural sites in space,a concept referred to as structure.In accordance with Shannon entropy,structure is analogous to information.Generally,the arrangement of atoms within a material,termed its structure,plays a pivotal role in dictating its properties.In addition to expanding the array of options for alloy composites,HEAs afford ample opportunities for diverse structural designs.The profound influence of distinct structural features on the exceptional behaviors of alloys is underscored by numer-ous examples.These features include remarkably high fracture strength with excellent ductility,antiballistic capability,exceptional radi-ation resistance,and corrosion resistance.In this paper,we delve into various unique material structures and properties while elucidating the intricate relationship between structure and performance.
基金Project supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2015BAB16B03)the National Nature Science Foundation of China(51504034,51674037)
文摘In order to improve the application values of Ce element, in this paper, rare earth chloride solution was used as raw material, the pH value was controlled by inorganic alkali, the ceria powders with special physical properties were prepared by carbon dioxide carbonization method. According to characterization of SEM, XRD, and TG-DSC, Ce（OH）3 prepared at pH = 7.5 exhibits smaller particle size than that prepared at other conditions. CeO2 precursor obtained by direct carbonization of Ce（OH）3 shows smaller particle size and narrow size distribution, CeO2 precursor forms at first by carbonization of Ce（OH）3 with the continuous addition of CO2 gas,and the chemical component is indicated to be Ce2 O（CO3）2·6 H2 O.Cubic phase CeO2 powders are obtained by calcined at 750 ℃ for 4 h. The mean particle size D（50） is0.941 μm, and particle size distribution is smaller than 1. The microscopic appearance is homogeneous,with a spherical-like shape and a grain size of 200-500 nm. The light quality characteristics of sedimentation volume and accumulation density are obviously better than those of carbonate precipitation products. The carbonization method can be used not only to obtain ultra-fine rare earth oxides with fine particle size, narrow distribution and high dispersion properties, but also to achieve the reuse of carbon dioxide greenhouse gas.
