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Precipitation kinetics and strengthening of M23C6 in novel G115 martensitic steel:Utilizing secondary normalizing

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Progress in Natural science:materials International 2024年第2期34卷 396-407页

作者： Chengxian Zhang Zhi Yuan Qiuzhi Gao Qingshuang Ma Hailian Zhang Jing Bai Huijie Zhang Liming Yu Huijun Li school of materials science and engineering Northeastern University school of Resources and materials Northeastern University at Qinhuangdao school of materials science & engineering Tianjin University school of Mechanical Materials and Mechatronic Engineering University of Wollongong

G115 martensitic steel is anticipated to be one of the preferred candidate materials in ultra-super critical(USC)power plants with steam temperatures above 650℃.Microstructure evolutions and mechanical properties of G115 martensitic steel after applying various heat treatment processes were investigated.The results demonstrate that the main precipitate in G115 martensitic steel after applying various heat treatment processes is M23C6 phase with Cr enrichment.The time required for M23C6 phase precipitation decreases with increasing secondary normalizing temperature and the extension in holding time according to its precipitation-temperature-time(PTT)curves.Volume fraction of M23C6 phase increases with increasing secondary normalizing temperature and holding time,which strengthens the inhibitory effect of precipitates on dislocations recovery and laths growth.Therefore,G115 martensitic steel can obtain the best mechanical properties after applying the highest secondary normalizing temperature and the longest holding time.In the current work,the excellent strength of G115 martensitic steel mainly derives from precipitates strengthening and laths strengthening.

关键词： G115 martensitic steel M23C6 phase Precipitation kinetics Secondary normalizing Strengthening mechanisms

Dynamic recrystallization mechanism, texture evolution development and mechanical characteristics of a Mg–8.7Gd–4.18Y–0.42Zr magnesium alloy by ECAP

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Progress in Natural science:materials International 2024年第2期34卷 376-388页

作者： Ling Zhang Yinglong Li school of materials science and engineering Northeastern University school of Mechanical and engineering Ningxia Institute of Science and Technology

Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstructures,dynamic recrystallization mechanism, texture development, and mechanical performance of GW94K(Mg–8.7Gd–4.18Y–0.42Zr wt. %) Mg alloy following ECAP-4 passes at 400°C and 3 mm/min. Results show that when high-temperature deformation is undertaken, twin formation is suppressed while dislocation slip is facilitated, increasing dislocation density during deformation. Following ECAP deformation, the sample displayed higher fracture elongation, TYS, and UTS than the as-solutioned GW94K alloy. In particular, the GW94K alloy performed well mechanically after ECAP-4 passes, with an ultimate TYS of 231 MPa, an UTS of 290 MPa, and an elongation of 14.8 %. DDRX and shear bands induce CDRX, both of which are important in plastic deformation. as well as in modifying microstructure and grain orientation during ECAP deformation.

关键词： Dynamic recrystallization mechanism Equal channel angular pressing Magnesium alloy Mechanical performance Mg-Gd-Y-Zr alloy Texture development

Boosting cycling stability by regulating surface oxygen vacancies of LNMO by rapid calcination

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Nano Research 2024年第4期17卷 2671-2677页

作者： Haoran Jiang Cuihua Zeng Wei Zhu Jiawei Luo Zhedong Liu Jingchao Zhang Rui Liu Yunhua Xu Yanan Chen Wenbin Hu school of materials science and engineering Tianjin UniversityTianjin 300072China school of materials science and engineering Shandong University of Science and TechnologyQingdao 266590China

Spinel LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)has attracted intensive interest for lithium-ion battery due to its high voltage and high energy density.However,severe capacity fade attributed to unstable surface structure has hampered its commercialization.Oxygen vacancies(OVs)tend to occur in the surface of the material and lead to surface structure reconstruction,which deteriorates the battery performance during electrochemical cycling.Here,we utilize high-temperature-shock(HTS)method to synthesize LNMO materials with fewer surface OVs.Rapid calcination drives lower surface OVs concentration,reducing the content of Mn^(3+)and surface reconstruction layers,which is beneficial to obtain a stable crystal structure.The LNMO material synthesized by HTS method delivers an initial capacity of 127 mAh·g^(-1) at 0.1 C and capacity retention of 81.6%after 300 cycles at 1 C,and exhibits excellent performance at low temperature.

关键词： ultrafast synthesis oxygen vacancy LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)cathode high-temperature-shock lithium-ion batteries

Role of micro-Ca/In alloying in tailoring the microstructural characteristics and discharge performance of dilute Mg-Bi-Sn-based alloys as anodes for Mg-air batteries

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Journal of Magnesium and Alloys 2024年第1期12卷 251-266页

作者： Fei-er Shangguan Wei-li Cheng Yu-hang Chen Ze-qin Cui Hui Yu Hong-xia Wang Li-fei Wang Hang Li Hua Hou school of materials science and engineering Taiyuan University of TechnologyTaiyuan 030024China school of materials science and engineering Hebei University of TechnologyTianjin 300132China school of materials science and engineering North University of ChinaTaiyuan 030051China

The influence of micro-Ca/In alloying on the microstructural charac teristics,electrochemical behaviors and discharge properties of extruded dilute Mg-0.5Bi-0.5Sn-based(wt.%)alloys as anodes for Mg-air batteries are evaluated.The grain size and texture intensity of the Mg-Bi-Sn-based alloys are significantly decreased after the Ca/In alloying,particularly for the In-containing alloy.Note that,in addition to nanoscale Mg_(3)Bi_(2)phase,a new microscale Mg_(2)Bi_(2)Ca phase forms in the Ca-containing alloy.The electrochemical test results demonstrate that Ca/In micro-alloying can enhance the electrochemical activity.Using In to alloy the Mg-Bi-Sn-based alloy is effective in restricting the cathodic hydrogen evolution(CHE)kinetics,leading to a low self-corrosion rate,while severe CHE occurred after Ca alloying.The micro-alloying of Ca/In to Mg-Bi-Sn-based alloy strongly deteriorates the compactness of discharge products film and mitigates the"chunk effect"(CE),hence the cell voltage,anodic efficiency as well as discharge capacity are greatly improved.The In-containing alloy exhibits outstanding discharge performance under the combined effect of the modified microstructure and discharge products,thus making it a potential anode material for primary Mg-air battery.

关键词： Mg-air batteries Mg-Bi-Sn based alloys Electrochemical behaviors Discharge properties

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Cobalt phosphide-based composites as anodes for lithium-ion batteries:From mechanism,preparation to performance

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Particuology 2024年第5期88卷 11-31页

作者： Bo Lan Yishan Wang Jialei Lu Dongdong Liu Chuncheng Wei Xueqian Zhang Xiaoxiao Huang Guangwu Wen school of materials science and engineering Shandong University of TechnologyZibo255000China school of materials science and engineering Harbin Institute of TechnologyHarbin150001China school of materials science and engineering Harbin Institute of TechnologyWeihai264209China

With the further requirements of electronic products and powered vehicles,the development of a new generation with low-voltage and high-capacity anode materials is crucial for lithium-ion batteries(LIBs).Transition metal phosphides,especially cobalt phosphide(CoP)composites,have become a research hotspot for LIBs anode materials in recent years due to their high theoretical specific capacity,low polarization,and suitable voltage plateau.This review first systematically discusses the lithium storage mechanism and preparation methods of CoP in current research.Subsequently,the applications of CoP anode materials in LIBs are categorically reviewed,including the composites of CoP with various types of carbon materials and heterostructures.Finally,the challenges and future development directions of CoP anode materials are summarized to provide guidance for further improving the lithium storage performance of CoP and its practical applications.

关键词： CoP Composites Preparation Anodes Lithium-ion batteries

Biomass-derived porous carbon with single-atomic cobalt toward high-performance aqueous zinc-sulfur batteries at room temperature

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Journal of Energy Chemistry 2024年第8期95卷 325-335页

作者： Shenfei Zhao Xiaoshuai Wu Jiliang Zhang Chunjie Li Zixiang Cui Weihua Hu Ruguang Ma Changming Li Institute for Clean Energy & Advanced materials School of Materials & Energy Southwest University Institute for materials science and Devices School of Materials Science and Engineering Suzhou University of Science and Technology school of materials science and engineering Dalian Jiaotong University

Aqueous zinc-sulfur batteries at room temperature hold great potential for next-generation energy storage technology due to their low cost, safety and high energy density. However, slow reaction kinetics and high activation energy at the sulfur cathode pose great challenges for the practical applications. Herein,biomass-derived carbon with single-atomic cobalt sites（MMPC-Co） is synthesized as the cathode in Zn-S batteries. The catalysis of single-atom Co sites greatly promotes the transform of cathode electrolyte interface（CEI） on the cathode surface, while offering accelerated charge transfer rate for high conversion reversibility and large electrochemical surface area（ECSA） for high electrocatalytic current. Furthermore,the rich pore structure not only physically limits sulfur loss, but also accelerates the transport of zinc ions.In addition, the large pore volume of MMPC-Co is able to relieve the stress effect caused by the volume expansion of Zn S during charge/discharge cycles, thereby maintaining the stability of electrode structure.Consequently, the sulfur cathode maintains a high specific capacity of 729.96 m A h g-1after 500 cycles at4 A g-1, which is much better than most cathode materials reported in the literature. This work provides new insights into the design and development of room-temperature aqueous Zn-S batteries.

关键词： Aqueous zinc-sulfur batteries Biomass-derived carbon Rich pore structure Single-atom catalysts Sulfur cathode

Weakly Polarized Organic Cation-Modified Hydrated Vanadium Oxides for High-Energy Efficiency Aqueous Zinc-Ion Batteries

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Nano-Micro Letters 2024年第7期16卷 169-186页

作者： Xiaoxiao Jia Chaofeng Liu Zhi Wang Di Huang Guozhong Cao Department of materials science and engineering University of WashingtonSeattleWA 98195USA school of materials science and engineering Tongji UniversityShanghai 201804People’s Republic of China

Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic characteristics,and high theoretical capacities.However,challenges such as vanadium dissolution,sluggish Zn^(2+)diffusion kinetics,and low operating voltage still hinder their direct application.In this study,we present a novel vanadium oxide([C_(6)H_(6)N(CH_(3))_(3)]_(1.08)V_(8)O_(20)·0.06H_(2)O,TMPA-VOH),developed by pre-inserting trimethylphenylammonium(TMPA+)cations into VOH.The incorporation of weakly polarized organic cations capitalizes on both ionic pre-intercalation and molecular pre-intercalation effects,resulting in a phase and morphology transition,an expansion of the interlayer distance,extrusion of weakly bonded interlayer water,and a substantial increase in V^(4+)content.These modifications synergistically reduce the electrostatic interactions between Zn^(2+)and the V-O lattice,enhancing structural stability and reaction kinetics during cycling.As a result,TMPA-VOH achieves an elevated open circuit voltage and operation voltage,exhibits a large specific capacity(451 mAh g^(-1)at 0.1 A g^(-1))coupled with high energy efficiency(89%),the significantly-reduced battery polarization,and outstanding rate capability and cycling stability.The concept introduced in this study holds great promise for the development of high-performance oxide-based energy storage materials.

关键词： Zinc-ion battery Vanadium oxide V_(2)O_(5)·nH_(2)O Pre-intercalation Interlayer engineering

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Nanocavity enriched CuPd alloy with high selectivity for CO2 electroreduction toward C2H4

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Rare Metals 2024年第4期43卷 1513-1523页

作者： Ze-Yu Zhang Hai-Bin Wang Fei-Fei Zhang Jing-Wei Li Xin-Zhuo Hu Si-Wei Yan Yi-Ming Bai Xun Zhang Gu-Rong Shen Peng-Fei Yin Jing Yang Cun-Ku Dong Jing Mao Hui Liu Xi-Wen Du Institute of New-Energy materials School of Materials Science and EngineeringTianjin University

Electrocatalysis of CO2reduction reaction is an effective way to convert CO2into high value-added products,but the selectivity of Cu-based catalysts for C2+products needs to be improved due to the high energy barrier of C-C coupling.Therefore,a viable catalyst design strategy to decrease energy barrier of C-C coupling should be put forward.Here,a nanocavity-enriched CuPd single atom alloy（CuPd SAA） catalyst is designed to promote CC coupling process.The faradaic efficiency of CuPd SAA for ethylene and C2+reaches 75.6% and 85.7% at-0.7 V versus reversible hydrogen electrode（RHE）,respectively.Based on the results given by in situ characterization,the porous hollow structure dramatically increases the ratio of the linear-bond*CO,thus enhancing the faradaic efficiency for ethylene.Density functional theory（DFT） calculation reveals that the Pd doping can regulate the electronic structure of neighboring Cu atoms to decrease the energy barrier of C-C coupling,further improving the faradaic efficiency.This work provides a new idea for designing catalyst with high selectivity for ethylene.

关键词： Adsorption configuration C–C coupling CO 2 electrocatalysis Ethylene Single atom alloy

Preparation of tungsten-particle-reinforced Zr-based bulk metallic glass composites by two-step spark plasma sintering:microstructure evolution,densification mechanism and mechanical properties

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Rare Metals 2024年第4期43卷 1793-1808页

作者： Yun-Fei Ma Pan Gong Mao Zhang Hui-E.Hu Zhen Peng Xiao Xu Xin Wang Mehdi Malekan Xue-Feng Tang Lei Deng Jun-Song Jin Xin-Yun Wang State Key Laboratory of materials Processing and Die and Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology Research Institute of Huazhong University of science and Technology in Shenzhen Department of Chemistry and materials Naval University of Engineering school of materials science and engineering Jiangsu University College of Machine Shanghai Dianji University school of Metallurgy and materials engineering College of EngineeringUniversity of Tehran

A new two-step spark plasma sintering(TSS)process with low-temperature pre-sintering and high-temperature final sintering has been successfully applied to prepare the tungsten-particle(Wp)-reinforced bulk metallic glass composites(Wp/BMGCs).Compared to normal spark plasma sintering(NS),the densification rate and relative density of Wp/BMGCs can be improved by selecting TSS with appropriate sintering pressure in the low temperature pre-sintering stage.However,the compressive strength and plastic strain of 30%Wp/BMGCs prepared by TSS are both higher than those of the samples prepared by NS.The TSS process can significantly enhance the compressive strength of 30%Wp/BMGCs by 12% and remarkably increase the plastic strain by 50%,while the trend is completely opposite for 50%Wp/BMGCs.Quasi-in situ experiments and finite element simulations reveal that uneven temperature distribution among particles during low-temperature pre-sintering causes local overheating at contact points between particles,accelerating formation of sintering neck between particles and plastic deformation of Wp.When the volume fraction of Wp is low,TSS can improve the interface bonding between particles by increasing the number of sintering necks.This makes the fracture mode of Wp/BMGCs being predominantly transgranular fracture.However,as the volume fraction of Wp increases,the adverse effects of Wp plastic deformation are becoming more and more prominent.The aggregated Wp tends to form a solid "cage structure" that hinders the bonding between particles at the interface;correspondingly,the fracture behavior of Wp/BMGCs is mainly dominated by intergranular fracture.Additionally,reducing the sintering pressure during the low-temperature pre-sintering stage of TSS has been shown to effectively decrease plastic deformation in Wp,resulting in a higher degree of densification and better mechanical properties.

关键词： Bulk metallic glass composites Tungsten particle Two-step spark plasma sintering Densification mechanism Mechanical properties