检索结果-南通市图书馆

Effects of processing parameters on fabrication defects,microstructure and mechanical properties of additive manufactured Mg–Nd–Zn–Zr alloy by selective laser melting process

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第6期12卷 2249-2266页

作者： Wenyu Xu Penghuai Fu Nanqing Wang Lei Yang Liming Peng Juan Chen Wenjiang Ding national engineering research center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite School of Materials Science and EngineeringShanghai Jiao Tong University800 Dongchuan RoadShanghai 200240China Shanghai Light Alloy Net Forming national engineering research center Co. LtdShanghai 201615China

Mg–3Nd–0.2Zn–0.4Zr(NZ30K,wt.%)alloy is a new kind of high-performance metallic *** combination of the NZ30K Magnesium(Mg)alloy and selective laser melting(SLM)process seems to be an ideal solution to produce porous Mg degradable ***,the microstructure evolution and mechanical properties of the SLMed NZ30K Mg alloy were not yet studied ***,the fabrication defects,microstructure,and mechanical properties of the SLMed NZ30K alloy under different processing parameters were *** results show that there are two types of fabrication defects in the SLMed NZ30K alloy,gas pores and unfused *** the increase of the laser energy density,the porosity sharply decreases to the minimum first and then slightly *** minimum porosity is 0.49±0.18%.While the microstructure varies from the large grains with lamellar structure inside under low laser energy density,to the large grains with lamellar structure inside&the equiaxed grains&the columnar grains under middle laser energy density,and further to the fine equiaxed grains&the columnar grains under high laser energy *** lamellar structure in the large grain is a newly observed microstructure for the NZ30K Mg *** laser energy density leads to finer grains,which enhance all the yield strength(YS),ultimate tensile strength(UTS)and elongation,and the best comprehensive mechanical properties obtained are YS of 266±2.1 MPa,UTS of 296±5.2 MPa,with an elongation of 4.9±0.68%.The SLMed NZ30K Mg alloy with a bimodal-grained structure consisting of fine equiaxed grains and coarser columnar grains has better elongation and a yield drop phenomenon.

关键词： Selective laser melting Mg alloy Processing parameter Lamellar structure Bimodal-grained structure

Synthesis of granulated Li_(1.33)Mn_(1.67)O_(4) via two antisolvent methods for lithium adsorption from gas-produced water

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical engineering 2024年第5期69卷 34-46页

作者： Jun Qiu Lu-Ri Bao Wei Guo Ying Yang Shu-Ying Sun national engineering research center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China

Gas-produced water is an accompanying wastewater in the natural gas extraction process,and it is a potential liquid lithium resource that contains a considerable amount of *** study investigated the feasibility of using manganese-based ion sieves to adsorb and extract lithium from gas-produced *** we focused on the applicability of two different granulation methods,extrusion and droplet,in gas-produced water *** types of H_(1.33)Mn_(1.67)O_(4) particles were prepared by the extrusion method(EHMO)and the droplet method(DHMO).The porosity of DHMO was much higher than that of EHMO,and the adsorption performance of DHMO increased with the decrease of binder *** prepared with a binder concentration of 0.14 g·ml^(-1)exhibited the best adsorption performance in gas-produced water,and the Li^(+)adsorption capacity could reach 25.14 mg·g^(-1).In gas-produced water,the adsorption equilibrium of DHMO only took 9 h,and the adsorption process conformed to the Langmuir model and pseudo-second-order kinetic *** pore diffusion model(PDM)could well describe its adsorption ***,DHMO showed a great selectivity to Li^(+),and the selectivity order of DHMO in gas-produced water was Li^(+)>Ba^(2+)>>Mg^(2+),Ca^(2+),Sr^(2+)>>Na^(+)>>K^(+).After 20 cycles,the Li^(+)adsorption capacity was still higher than 17.30 mg·g^(-1),and the rate of manganese dissolution was less than 1%.

关键词： Gas-produced water Granulation Li_(1.33)Mn_(1.67)O_(4)

OSDA-free synthesis of FeZSM-22 zeolite from natural minerals for n-octane hydroisomerization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical engineering 2024年第2期66卷 51-59页

作者： Tiesen Li Ting Chen Yinghui Ye Peng Dong TinghaiWang Qingyan Cui Chan Wang Yuanyuan Yue national engineering research center of Chemical Fertilizer Catalyst College of Chemical EngineeringFuzhou UniversityFuzhou 350002China Qingyuan Innovation Laboratory Quanzhou 362801China

A seed-directed approach to synthesizing Fe ZSM-22 zeolite without organic structure directing agent(OSDA)was developed by using Fe-rich diatomite as all aluminum and iron *** Fe ZSM-22zeolite with optimal crystallinity and purity can be obtained by systematically adjusting feed composition and synthesis *** show that Fe ZSM-22 zeolite synthesized with OSDA-free owns high crystallinity,obvious thin needle-shaped morphology and high Bronsted/Lewis acid ***,when used for n-octane hydroisomerization reaction,its derived catalyst exhibits the best catalytic performance reflected by the highest selectivity to C_(8)isomers compared to the two reference catalysts prepared based on a Fe-containing and a Fe-free ZSM-22 synthesized through an OSDA-directed route from natural diatomite and conventional chemicals,*** work provides an alternative route to sustainably synthesizing heteroatomic zeolites with high performance.

关键词： FeZSM-22 zeolite OSDA-free synthesis Natural minerals n-octane hydroisomerization

Strength and ductility optimization of HPDC AlSi8MgCuZn2 alloys by modifying pre-aging treatment

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第4期21卷 343-351页

作者： Yuan-hang Jiang Hui-ting Zheng Fei Liu Hai-dong Zhao national engineering research center of Near-net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

Considering the components produced by high pressure die casting(HPDC)process usually with ultra-large sizes and complex morphologies,high temperature solid solution treatment is not a suitable method to further improve their mechanical *** this study,two-stage aging treatment with different pre-aging times was designed and employed to further improve the mechanical properties of HPDC Al8SiMgCuZn *** characteristics of precipitates were evaluated by a transmission electron microscope(TEM),and the precipitation strengthening mechanism was *** results reveal that the strengthening is mainly contributed by the precipitation ofβ″phase after two-stage aging,and the number density and size of the precipitates are significantly depended on the pre-aging *** number density of precipitates is increased with the pre-aging time prolonged from 0 h to 4 h,and then decreases with the further increase of pre-aging time from 4 h to 6 *** precipitates with the highest density and smallest size are observed after pre-aging for 4 *** pre-aged at 100℃for 4 h and then artificial aged at 200℃for 30 min,the yield strength of 207 MPa,ultimate tensile strength of 325 MPa and elongation of 7.6%are achieved.

关键词： high pressure die cast aluminum alloy microstructural heterogeneity mechanical properties precipitation strengthening two-stage aging

Microstructural evolution and deformation behavior of friction stir welded twin-induced plasticity steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第2期169卷 68-81页

作者： Ke Qiao Kuaishe Wang Jia Wang Zhengyang Hao Yating Xiang Peng Han Jun Cai Qi Yang Wen Wang School of Metallurgical engineering National and Local Joint Engineering Research Center for Functional Materials ProcessingXi’an University of Architecture and TechnologyXi’an 710055China Shanghai research Institute of Materials Shanghai 200437China

The weldability of twin-induced plasticity(TWIP)steel with ultra-high strength via friction stir welding(FSW)technique was investigated,and microstructural evolution and deformation behavior of whole and micro-zones of FSW TWIP joint were studied for the first *** results showed that the content of recrystallized grains in the stir zone(SZ)increased from 10.5%of basal material(BM)to 14.2%,and that of heat affected zone(HAZ)increased to 78.6%.The percentage of annealing twins decreased from 26.8%in BM to 11%in SZ,while increased to 35%in *** with the BM,the ultimate tensile strength and yield strength of the FSW joint increased to 1036 and 550 MPa,respectively,reaching 106.7%and 110.9%of BM,*** elongation of the entire joint was 50.5%,which was lower than that of BM due to the nonuniform deformation during the tensile *** engineering strain was mainly concentrated in BM and SZ and transferred to each other during the tensile test,while the engineering strain in HAZ was always the ***,the tensile fracture occurred in the *** order of ultimate tensile strength of micro-zones in the FSW joint was as follows:HAZ>BM≈*** order of yield strength was as follows:HAZ>BM>SZ.

关键词： Twin-induced plasticity steel Friction stir welding Microstructure Mechanical property Deformation behavior

Resource Allocation for Channel Estimation in Reconfigurable Intelligent Surface-Aided Multi-Cell Networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2024年第1期9卷 64-79页

作者： Yining Xu Sheng Zhou Department of Electronic engineering Beijing National Research Center for Information Science and TechnologyTsinghua UniversityBeijing 100084China

Reconfigurable intelligent surface(RIS)is a promising solution to deal with the blockage-sensitivity of millimeter wave band and reduce the high energy consumption caused by network densification. However, deploying large scale RISs may not bring expected performance gain due to significant channel estimation overhead and non-negligible reflected *** this paper,we derive the analytical expressions of the coverage probability, area spectrum efficiency(ASE)and energy efficiency (EE)of a downlink RIS-aided multi-cell *** order to optimize the network performance, we investigate the conditions for the optimal number of training symbols of each antenna-to-antenna and antenna-to-element path (referred to as the optimal unit training overhead) in channel *** study shows that:1)RIS deployment is not“the more, the better”, only when blockage objects are dense should one deploy more RISs;2) the coverage probability is maximized when the unit training overhead is designed as large as possible;3)however,the ASE-and-EE-optimal unit training overhead exists. It is a monotonically increasing function of the frame length and a monotonically decreasing function of the average signal-to-noise-ratio (in the high signal-to-noise-ratio region). Additionally,the optimal unit training overhead is smaller when communication nodes deploy particularly few or many antennas.

关键词： reconfigurable intelligent surface multi-cell network directional transmissions channel estimation resource allocation stochastic geometry

Functional Optical Fiber Sensors Detecting Imperceptible Physical/Chemical Changes for Smart Batteries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第8期16卷 268-308页

作者： Yiding Li Li Wang Youzhi Song Wenwei Wang Cheng Lin Xiangming He Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084People’s Republic of China national engineering research center of Electric Vehicles Beijing Institute of Technology(BIT)Beijing 100081People’s Republic of China Shenzhen Automotive research Institute of BIT(Shenzhen research Institute of national engineering research center of Electric Vehicles) Shenzhen 518118People’s Republic of China

The battery technology progress has been a contradictory process in which performance improvement and hidden risks *** the battery is still a“black box”,thus requiring a deep understanding of its internal *** battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing *** paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety *** paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”*** the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed *** advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system ***,with the help of smart batteries in the future,the importance of consistency can be weakened or even *** application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.

关键词： Smart battery Advanced embedded optical fiber sensor Battery internal physical/chemical state Quality-reliability-life characteristic

Microstructure evolution and strengthening mechanism of high -performance powder metallurgy TA15 titanium alloy by hot rolling

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1426-1436页

作者： Ying Gao Ce Zhang Jiazhen Zhang Xin Lu Beijing Advanced Innovation center for Materials Genome engineering State Key Laboratory for Advanced Metals and MaterialsInstitute for Advanced Ma-terials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China national engineering research center for Advanced Rolling Technology National Engineering Research Center for Flat Rolling EquipmentInstitute of Engin-eering TechnologyUniversity of Science and Technology BeijingBeijing 100083China

Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying *** this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium alloy plates were prepared by cold press-ing sintering combined with high-temperature hot *** microstructure and mechanical properties under different process paramet-ers were *** microscope,electron backscatter diffraction,and others were applied to characterize the microstructure evolution and mechanical properties strengthening *** results showed that the chemical compositions were uniformly dif-fused without segregation during sintering,and the closing of the matrix craters was accelerated by increasing the sintering *** block was hot rolled at 1200℃ with an 80%reduction under only two passes without *** strength and elongation of the plate at 20–25℃ after solution and aging were 1247 MPa and 14.0%,respectively,which were increased by 24.5%and 40.0%,respect-ively,compared with the as-sintered alloy at 1300℃.The microstructure was significantly refined by continuous dynamic recrystalliza-tion,which was completed by the rotation and dislocation absorption of the substructure surrounded by low-angle grain *** hot rolling combined with heat treatment,the strength and plasticity of PM-TA15 were significantly improved,which resulted from the dense,uniform,and fine recrystallization structure and the synergistic effect of multiple slip systems.

关键词： elemental powder powder metallurgy titanium alloy hot rolling strength and plasticity

Effects of Sinusoidal Vibration of Crystallization Roller on Composite Microstructure of Ti/Al Laminated Composites by Twin-Roll Casting

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 196-205页

作者：李励杜凤山 national engineering research center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004China College of Mechanical engineering Yanshan UniversityQinhuangdao 066004China

A new,innovative vibration cast-rolling technology of “electromagnetic stirring+dendrite breaking+asynchronous rolling” was proposed with the adoption of sinusoidal vibration of crystallization roller to prepare Ti/Al laminated composites,and the effect of sinusoidal vibration of crystallization roller on composite microstructure was investigated in *** results show that the metallurgical bonding of titanium and aluminum is realized by mesh interweaving and mosaic meshing,instead of transition bonding by forming metal compound *** meshing depth between titanium and aluminum layers (6.6μm) of cast-rolling materials with strong vibration of crystallization roller (amplitude 0.87 mm,vibration frequency 25 Hz) is doubled compared with that of traditional cast-rolling materials (3.1μm),and the composite interfacial strength(27.0 N/mm) is twice as high as that of traditional cast-rolling materials (14.9 N/mm).This is because with the action of high-speed superposition of strong tension along the rolling direction,strong pressure along the width direction and rolling force,the composite linearity evolves from "straight line" with traditional casting-rolling to "curved line",and the depth and number of cracks in the interface increases greatly compared with those with traditional cast-rolling,which leads to the deep expansion of the meshing area between interfacial layers and promotes the stable enhancement of composite quality.

关键词： laminated composites sinusoidal vibration composite microstructure