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A multi-objective optimization based on machine learning for dimension precision of wax pattern in turbine blade manufacturing

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Advances in Manufacturing 2024年第3期12卷 428-446页

作者： Jing Dai Song-Zhe Xu Chao-Yue Chen Tao Hu San-San Shuai Wei-Dong Xuan Jiang Wang Zhong-Ming Ren State Key Laboratory of Advanced Special Steels School of Materials Science and EngineeringShanghai UniversityShanghai200444People’s Republic of China

Wax pattern fabrication in the investment casting of hollow turbine blades directly determines the dimension accuracy of subsequent casting,and therefore significantly affects the quality of final *** this work,we develop a machine learning-based multi-objective optimization framework for improving dimension accuracy of wax pattern by optimizing its process *** consider two optimization objectives on the dimension of wax pattern,i.e.,the surface warpage and core *** active learning of Bayesian optimization is employed in data sampling to determine process parameters,and a validated numerical model of injection molding is used to compute objective results of dimension under varied process *** collected dataset is then leveraged to train different machine learning models,and it turns out that the Gaussian process regression model performs best in prediction accuracy,which is then used as the surrogate model in the optimization framework.A genetic algorithm is employed to produce a non-dominated Pareto front using the surrogate model in searching,followed by an entropy weight method to select the most optimal solution from the Pareto *** optimized set of process parameters is then compared to empirical parameters obtained from previous trial-and-error experiments,and it turns out that the maximum and average warpage results of the optimized solution decrease 26.0%and 20.2%,and the maximum and average errors of wall thickness compared to standard part decrease from 0.22 mm and 0.0517 mm using empirical parameters to 0.10 mm and 0.0356 mm using optimized parameters,*** framework is demonstrated capable of addressing the challenge of dimension control arising in the wax pattern production,and it can be reliably deployed in varied types of turbine blades to significantly reduce the manufacturing cost of turbine blades.

关键词： Hollow turbine blade Wax pattern fabrication Dimension control Multi-objective optimization Machine learning Numerical simulation

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A“bricks-and-mortar”structured graphene oxide/polyvinyl alcohol coating:Enhanced water interfacial lubrication and durability

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Friction 2024年第12期12卷 2657-2678页

作者： Hanglin LI Lin DING Jingchun ZHANG Zhaoyang GUO Yazhuo SHANG Honglai LIU Xiangqiong ZENG Jiusheng LI Key Laboratory for Advanced Materials School of Chemistry&Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Laboratory for Advanced Lubricating Materials Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

Coatings serve as ideal protective films for mechanical systems,providing dependable as well as efficient lubrication because of their unique structure along with outstanding tribological *** by the“bricks-and-mortar”structure,we prepared layered graphene oxide(GO)composite finishes strengthened with polyvinyl alcohol(PVA)and *** study demonstrates that the tribological properties of the GO-based coating on 304 stainless steel(SS304)are potentially greatly affected through PVA,GO,and *** optimizing the composition,we achieved the PVA_(40 wt%)/GO_(0.01 wt%)/borax composite coating,which exhibited the lowest average coefficient of friction(COF)of 0.021±0.003(a 97.86%reduction compared to control SS304)with minimal wear and abrasion even in a water *** found that the enhanced mechanical characteristics as well as elastic recovery within the coating were attributed to the hydrogen bonds and cross-linking between PVA and borax,which led to stress *** friction was further aided by the formation of a hydrated layer at the friction *** a result,the coating demonstrated remarkable durability,maintaining a low COF during long sliding distances(576 m,28,800 cycles,significantly longer than previously reported)without breaking.

关键词： graphene oxide coating water lubrication anti-wear properties durability

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Highly selective photocatalytic CO_(2) reduction to ethylene in pure water by Nb_(2)O_(5) nanoparticles with enriched surface –OH groups under simulated solar illumination

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Journal of advanced Ceramics 2023年第8期12卷 1641-1654页

作者： Haoyu Zhang Shuang Gao Haitao Guan Weiyi Yang Qi Li Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Photocatalytic CO_(2) reduction to valuable chemical compounds could be a promising approach for carbon-neutral *** this work,a simple and robust thermal decomposition process was developed with ammonium carbonate((NH4)2CO3)as both precipitation agent and sacrificial template to produce fine Nb_(2)O_(5) nanoparticles with the rich existence of surface hydroxyl(–OH)*** was found by density functional theory(DFT)calculations and experiments that the rich existence of the surface–OH groups enhanced the adsorption of both reactants(CO_(2) and H_(2)O molecules)for the photocatalytic CO_(2) reduction on these fine Nb_(2)O_(5) nanoparticles,and the highly selective conversion of CO_(2) to the high-value chemical compound of ethylene(C_(2)H_(4),~68μmol·g^(−1)·h^(−1) with~100%product selectivity)was achieved under simulated solar illumination without usage of any sacrificial agents or noble metal *** synthesis process may also be readily applied as a surface engineering method to enrich the existence of the surface–OH groups on various metal oxide-based photocatalysts for a broad range of technical applications.

关键词： photocatalytic CO_(2)reduction niobium oxide nanoparticles thermal decomposition surface hydroxyl(-OH)groups simulated solar illumination

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Enhanced photocatalytic N_(2) fixation using KNbO3/Bi_(4)O_(5)Br_(2) type Ⅱ heterojunction

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Frontiers of Chemical science and engineering 2024年第6期18卷 85-97页

作者： Lin Yue Zhihao Zeng Xujie Ren Shude Yuan Chuanqi Xia Xin Hu Leihong Zhao Lvchao Zhuang Yiming He Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004China Department of Materials Science and Engineering Zhejiang Normal UniversityJinhua 321004China

The fabrication of heterojunction catalysts is an effective strategy to enhance charge separation efficiency,thus boosting the performance of *** work presents the synthesis and investigation of a novel KNbO_(3)/Bi_(4)O_(5)Br_(2) heterostructure catalyst for photocatalytic N_(2)-to-NH_(3) conversion under light *** morphology analysis revealed KNbO_(3) microcubes embedded within Bi_(4)O_(5)Br_(2) nanosheets,the composite exhibited no significant improvement in specific surface area or optical property compared to Bi_(4)O_(5)Br_(2) due to the relatively wide band gap and low surface area of KNbO_(3).The main contribution lies in the enhanced separation efficiency of photogenerated electrons and ***,the band structure analysis suggests that KNbO_(3) and Bi_(4)O_(5)Br_(2) exhibit suitable band potentials to form a type II *** from the higher Fermi level of KNbO_(3) than Bi_(4)O_(5)Br_(2),the electron drift at the contact region thus occurs and leads to the formation of a built-in electric field with the direction from KNbO_(3) to Bi_(4)O_(5)Br_(2),accelerating electron migration and improving the operational efficiency of the ***,the KNbO_(3)/Bi_(4)O_(5)Br_(2) catalyst shows an increased photoactivity,achieving an NH_(3) generation rate 1.78 and 1.58 times those of KNbO_(3) and Bi_(4)O_(5)Br_(2),*** work may offer valuable insights for the design and synthesis of heterojunction composite photocatalysts.

关键词： KNbO_(3)/Bi_(4)O_(5)Br_(2) heterojunction photocatalytic N_(2)fixation charge separation

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Recent Advances in High‑Efficiency Electrocatalytic Water Splitting Systems

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Electrochemical Energy Reviews 2023年第1期6卷 1-38页

作者： Xian‑Wei Lv Wen‑Wen Tian Zhong‑Yong Yuan Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) School of Materials Science and EngineeringNankai UniversityTianjin 300350China

Electrocatalytic water splitting driven by renewable energy input to produce clean hydrogen(H_(2))has been widely considered a prospective approach for a future hydrogen-based ***,the development of industrial alkaline water electrolyzers is hindered due to their unfavorable thermodynamics with high overpotential for delivering the whole process,caused by sluggish kinetics involving four-electron *** exploration of water electrolysis with low energy consumption and high efficiency is urgently required to meet the ever-growing energy storage and portfolio *** review emphasizes the strategies proposed thus far to pursue high-efficiency water electrolysis systems,including from the aspects of electro-catalysts(from monofunctional to bifunctional),electrode engineering(from powdery to self-supported),energy sources(from nonrenewable to renewable),electrolytes(from pure to hybrid),and cell configurations(from integrated to decoupled).Critical appraisals of the pivotal electrochemistry are highlighted to address the challenges in elevating the overall efficiency of water ***,valuable insights for the future development directions and bottlenecks of advanced,sustainable,and high-efficiency water splitting systems are outlined.

关键词： Electrocatalytic water splitting Hydrogen-based society Electrode engineering Cell configurations Challenges and perspectives

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Effect of oxygen addition and annealing time on microstructure and mechanical properties of Ti-34Nb alloy

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Journal of Iron and Steel Research International 2023年第1期30卷 158-164页

作者： Jun-shuai Wang Wen-long Xiao Lei Ren Yu Fu Chao-li Ma Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

The effect of oxygen addition and annealing time on microstructure and mechanical properties of Ti-34Nb and Ti-34Nb-0.2O alloys was *** addition of O suppresses the martensitic *** phase composition changes from singleα''phase toα''+βphases with oxygen *** addition of oxygen increases strength significantly at as-received,cold-rolled,and annealed alloys through solid solution *** accumulation of abundance of defects and grain refinement introduced by cold rolling have a significant strengthening effect but also damage *** addition of oxygen increasesα/βtransformation temperature and promotes the precipitation ofαphase during annealing in Ti-34Nb-0.2O alloy.αprecipitates can inhibit grain growth during *** strength decreases with annealing time increased due to the increase in grain size in Ti-34Nb alloy,while the strength increases in Ti-34Nb-0.2O alloy mainly due to the precipitation ofα*** cold rolling followed by annealing and addition of oxygen can improve the properties of alloys.

关键词： Titanium alloy Oxygen addition Annealing time αprecipitate

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A room-temperature magnetic semiconductor from a Co-Fe-Nb-B metallic glass

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science China(Physics,Mechanics & Astronomy) 2023年第4期66卷 94-99页

作者： Yu-Zhang Jiao Dmitry VLouzguine-Luzgin Ke-Fu Yao Zheng-Jun Zhang Na Chen Laboratory for Advanced Materials Processing Technology(MOE) State Key Laboratory of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials(MOE) Schoolof Materials Science and EngineeringTsinghua UniversityBeijing 100084China Advanced Institute for Materials Research(WPI-AIMR) Tohoku UniversitySendai 980-8577Japan Mathematics for Advanced Materials-OIL National Institute of Advanced Industrial Science and Technology(AIST)Sendai 980-8577Japan

Magnetic semiconductors with Curie temperatures higher than room temperature show potential for developing spintronic devices with combined data processing and storage functions for next-generation computing *** this study,we present an n-type Co_(19.8)Fe_(8.6)Nb_(4.3)B_(6.0)O_(61.3) magnetic semiconductor with a high Curie temperature of~559 *** magnetic semiconductor has a room-temperature resistivity of~2.10×10^(4)Ωcm and a saturation magnetization of~76 emu/cm^(3).The n-type Co_(19.8)Fe_(8.6)Nb_(4.3)B_(6.0)O_(61.3)magnetic semiconductor was deposited on p-type silicon to form a heterojunction,exhibiting a rectifying *** results provide the design principles for discovering high Curie temperature magnetic semiconductors with determined conduction types,which would play an essential role in realizing nonvolatile spin-based transistors that break free from the confines of currently established Si-based information technology.

关键词： magnetic semiconductor ferromagnetic metallic glass high Curie temperature

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Ultrasonic-assisted Hydrothermal Synthesis Autoclaved Bricks from Municipal Solid Waste Incineration Fly Ash and Coal Fly Ash(MSWI-FA)

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Journal of Wuhan University of Technology(materials science) 2025年第2期40卷 439-448页

作者： GUO Xiaolu HU Jiajun WANG Cheng Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and EngineeringTongji UniversityShanghai 201804China School of Materials Science and Technology Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China

Municipal solid waste incineration fly ash(MSWI)is considered as one of the hazardous wastes and requires to be well disposed to reduce the contaminant to the *** to the production of coal fly ash(FA)bricks,MSWI and FA were utilized to prepare autoclaved MSWI-FA block ***-assisted hydrothermal synthesis technology was used for production to explore the effect of ultrasonic *** strength,dry density,and water absorption tests were conducted to determine the optimal ultrasonic *** pre-treating mechanisms were investigated by SEM,FT-IR,particle size analysis,and ***,the micro-analyses of block samples were *** heavy metal leaching concentration was studied to assess the environmental *** experimental results show that the ultrasonic pre-treating time,water bath temperature,and ultrasonic power of 3 h,30℃,and 840 W are the optimal,under which the compressive strength,dry density,and water absorption were 8.14 MPa,1417.48 kg/m^(3),and 0.38,*** is shown that ultrasound destroys the surface structure of raw materials and smaller FA particles embed into *** particle size distribution of pre-treated raw materials mixture is wider and total pore volume is decreased by 6.3%.During hydrothermal processing,more Al-substituted tobermorite crystals are generated,which is the main source of higher strength and smaller pore volume of prepared block *** solidification/stabilization rates of Cu,Pb,and Zn increased by 30.77%,4.76%,and 35.29%,*** study shows a feasible way to utilize MSWI as raw material for construction.

关键词： municipal solid waste incineration fly ash coal fly ash ultrasonic pre-treatment hydrothermal synthesis environmental safety

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Oxidation behavior and microstructural evolution of FeCoNiTiCu five-element high-entropy alloy nanoparticles

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Journal of materials science & Technology 2024年第10期177卷 133-141页

作者： H.Bai R.Su R.Z.Zhao C.L.Hu L.Z.Ji Y.J.Liao Y.N.Zhang Y.X.Li X.F.Zhang Key Laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Institute of Advanced Magnetic Materials College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhou310012China

High-entropy alloys(HEAs)have attracted extensive attention ascribed to their unique physical and chemical properties induced by the cocktail ***,their oxidation behaviors,in particular at nanoscale,are still lack because of multi-element complexity,which could also be completely differ-ent from the bulk *** this work,we synthesized FeCoNiTiCu five-element HEA nanopar-ticles(NPs)with uniform elemental distribution by arc-discharging approach,and further investigated their oxidation behaviors at 250 ℃,and 350 ℃.The morphology,structure and element distribution of NPs were analyzed by transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS)and electron energy loss spectroscopy(EELS).The surface oxidation in FeCoNiTiCu NPs during the high-temperature process can induce nanoscale pores at core/shell interfaces by Kirkendall effect,and even the eventual coalescence into a single ***,the oxidation states of NPs with diameters(d)varying from 60 to 350 nm were analyzed in detail,revealing two typical configurations:hollow(d<150 nm)and yolk-shell structures(d>150 nm).The experimental results were complemented by first-principles calculations to investigate the diffusion behaviors of five elements,evidencing that the surface oxidation strongly alters the surface segregation preferences:(1)in the initial stage,Cu and Ni appear to prefer segregating on the surface,while Co,Ti and Fe tend to stay in the bulk;(2)in the oxidation process,Cu prefers to stay in the center,while Ti segregates to the surface ascribed to the reduced po-tential *** study gives new insights into oxidation of nanoscale HEA,and also provides a way for fabrication of high-entropy oxides with controllable architectures.

关键词： High-entropy alloy Nanoparticles Oxidation Kirkendall effect Exchange bias effect

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An MOF-Based Single-Molecule Propylene Nanotrap for Benchmark Propylene Capture from Ethylene

Chem and Bio Engineering

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Chem and Bio engineering 2024年第11期1卷 952-959页

作者： Wang, Jia-Xin Zhang, Teng-Fei Pei, Jiyan Liu, Di Wang, Yu-Bo Gu, Xiao-Wen Qian, Guodong Li, Bin State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and Engineering Zhejiang University Hangzhou310027 China

Highly selective capture and separation of propylene (C3H6) from ethylene (C2H4) presents one of the most crucial processes to obtain pure C2H4 in the petrochemical industry. The separation performance of current physisorbents is commonly limited by insufficient C3H6 binding affinity, resulting in poor low-pressure C3H6 uptakes or inadequate C3H6/C2H4 selectivities. Herein, we realize a unique single-molecule C3H6 nanotrap in an ultramicroporous MOF material (Co(pyz)[Pd(CN)4], ZJU-74a-Pd), exhibiting the benchmark C3H6 capture capacity at low-pressure regions. This MOF-based nanotrap features the sandwichlike strong multipoint binding sites and the perfect size match with C3H6 molecules, providing an ultrastrong C3H6 binding affinity with the maximal Qst value (55.8 kJ mol-1). This affords the nanotrap to exhibit one of the highest C3H6 uptakes at low pressures (60.5 and 103.8 cm3 cm-3 at 0.01 and 0.1 bar) and record-high C3H6/C2H4 selectivity (23.4). Theoretical calculations reveal that the perfectly size-matched pore cavities combined with sandwichlike multibinding sites enable this single-molecule C3H6 nanotrap to maximize the C3H6 binding affinity, mainly accounting for its record low-pressure C3H6 capture capacity and selectivity. Breakthrough experiments further confirm its excellent separation capacity for actual 1/99 and 50/50 C3H6/C2H4 mixtures, affording the remarkably high pure C2H4 productivities of 17.1 and 3.4 mol kg-1, respectively. © 2024 The Authors. Co-published by Zhejiang University and American Chemical Society.

关键词： Binding sites

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