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Journal of Iron and Steel Research International 2024年第8期31卷 2002-2013页

作者： Shuai Wang Jie Li Li-yang Zeng Xun-wei Zuo Nai-lu Chen Yong-hua Rong shanghai key laboratory of materials laser processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The metastable retained austenite(RA)plays a significant role in the excellent mechanical performance of quenching and partitioning(Q&P)steels,while the volume fraction of RA(V_(RA))is challengeable to directly predict due to the complicated relationships between the chemical composition and process(like quenching temperature(Qr)).A Gaussian process regression model in machine learning was developed to predict V_(RA),and the model accuracy was further improved by introducing a metallurgical parameter of martensite fraction(fo)to accurately predict V_(RA) in Q&P *** developed machine learning model combined with Bayesian global optimization can serve as another selection strategy for the quenching temperature,and this strategy is very effcient as it found the"optimum"Qr with the maximum V_(RA) using only seven consecutive *** benchmark experiment also reveals that the developed machine learning model predicts V_(RA) more accurately than the popular constrained carbon equilibrium thermodynamic model,even better than a thermo-kinetic quenching-partitioning-tempering-local equilibrium model.

关键词： Q&P steel Retained austenite fraction Machine learning Quenching temperature Gaussian process regression model

Highly active and durable La_(0.6) Ca_(0.4)(CrMnFeCo_(2)Ni)O_(3) high entropy perovskite oxide as electrocatalyst for oxygen evolution reaction in alkaline media

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Journal of materials Science & Technology 2024年第1期168卷 71-78页

作者： Xiaoqiang Ji Fan Yang Yunzhu Du Jing Li Jianguo Li Qiaodan Hu shanghai key laboratory of materials laser processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Oxygen evolution reaction(OER)is the imperative reaction for many energy storage and conversion devices such as recharge-able metal-air batteries and electrochemical water splitting[1].OER is a complex 4-electron process with sluggish kinetics and therefore requires electrocatalysts to overcome the high *** oxide(RuO_(2))and iridium oxide(IrO_(2))catalysts can promote the OER process remarkably[2-4],however,their ex-tremely high cost,natural scarcity,and long-term instability con-strain their scale-up application in clean-energy technologies[5,6].It is crucial to develop inexpensive,highly efficient,and durable electrocatalysts for OER.

关键词： entropy alkaline perovskite

Effect of Post-weld Heat Treatment on the Microstructure and Mechanical Properties of 2.25Cr-1Mo-0.25V Ultra-Thick Steel Plate

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1104-1114页

作者： Yanyang Wu Zongye Ding Wenquan Lu Jingchao Hou Qiaodan Hu Jianguo Li shanghai key laboratory of materials laser processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China State key laboratory of Advanced Special Steel Shanghai UniversityShanghai200444China School of Mechatronic Engineering and Automation Foshan UniversityFoshan528225GuangdongChina WuYang Iron and Steel Wugang450000HenanChina

Ensuring the homogeneous and excellent mechanical properties of 2.25Cr-1Mo-0.25V ultra-thick steel plate is the key to the production of hydrogenation reactor ***,it is required to understand the heterogeneity of microstructures and properties of ultra-thick plate after heat *** this work,the effect of post-weld heat treatment(PWHT)on the strength,plasticity,toughness and microstructures of the 193-mm-thick steel plate was investigated,and the formation mechanism of heterogeneity was *** PWHT decreased the room-and high-temperature yield strength(YS)and ultimate tensile strength(UTS)of the steel plate after normalizing and tempering(NT),while the room-and high-temperature YS and UTS decreased from the surface to the center of 193-mm-thick steel *** was attributed to the enhanced decomposition of martensite-austenite(M-A)constituents and coarsening of grains and precipitated carbides.

关键词： Cr-Mo steel Ultra-thick steel plate Microstructure Mechanical properties Heterogeneity

Bulging Distortion of Austenitic Stainless Steel Sheet on the Partially Penetrated Side of Non-Penetration Lap laser Welding Joint

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 286-295页

作者： Chengwu Yao Enze Liu Jiaming Ni Binying Nie shanghai key laboratory of materials laser processing and Modification School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China shanghai Aerospace Precision Machinery Institute Shanghai 201600China Chemical and Biological Engineering College Yichun UniversityYichun 336000China

Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost ***,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration *** this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser *** addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive *** results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a *** findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.

关键词： Non-penetration lap laser welding Bulging distortion Austenitic stainless steel Compressive stress Tension stress

Arc and Droplet Behaviors in Horizontal Short-Arc Pulsed Gas Metal Arc Welding of 9%Ni Steel with ERNiCrMo-3 Welding Wire

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Journal of shanghai Jiaotong university(Science) 2024年第2期29卷 361-376页

作者：刘轶玮华学明吴东升李芳蔡艳王欢杨修荣 shanghai key laboratory of Material laser processing and Modification Shanghai Jiao Tong UniversityShanghai 200240China Hudong-Zhonghua Shipbuilding(Group)Co. Ltd.Shanghai 200129China Zhuhai Cowin Welding Equipment&Consumables Co. Ltd.Zhuhai 519015GuangdongChina

Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding *** of short-circuit current was used to reduce *** length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to ***-arc P-GMAW with or without arc length stabilizer was *** droplet transfer,arc behaviors and weld bead profiles were investigated and compared based on the high-speed photography and observation of weld *** the arc length stabilizer was deactivated,the arc length was unstable and too *** droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit *** was also a small proportion of short circuit complete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit *** arc length stabilizer,droplet transfer modes were short circuit complete transfer and spray *** spray transfer had the largest droplet impact,no short circuit and no *** the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were *** provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the incomplete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.

关键词： droplet transfer arc behaviors weld bead formation short-arc pulsed gas metal arc welding(P-GMAW) high nickel alloy 9%Ni steel

Application of novel constrained friction processing method to produce fine grained biomedical Mg-Zn-Ca alloy

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Journal of Magnesium and Alloys 2024年第2期12卷 516-529页

作者： Ting Chen Banglong Fu Junjun Shen Uceu F.H.R.Suhuddin Björn Wiese Yuanding Huang Min Wang Jorge F.dos Santos Jean Pierre Bergmann Benjamin Klusemann Solid State materials processing Institute of Material MechanicsHelmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht 21502Germany Functional Magnesium materials Institute of Metallic BiomaterialsHelmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht 21502Germany shanghai key laboratory of materials laser processing and Modification Shanghai Jiao Tong UniversityDongchuan Road 800Shanghai 200240China Applied materials and Manufacturing Energy and Environment DivisionPacific Northwest National LaboratoryPO Box 999RichlandWA 99352USA Production Technology Group Technisiche Universität IlmenauGustav-Kirchhoff-Platz 2Ilmenau 98693Germany Institute for Production Technology and Systems Leuphana University of LüneburgUniversitätsallee 1Lüneburg 21335Germany

In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was *** CFP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were *** to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process *** compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear *** the base material to the rod,the material experienced three stages,*** by the tool,upward flow with additional tilt,followed by upward *** microstructural evolution was revealed by“stop-action”*** microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DRX)as well as particle stimulated nucleation,while that within the rod is related to DRX combined with grain growth.

关键词： Constrained friction processing Magnesium alloys Microstructure Mechanical properties Grain refinement Plastic deformation

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

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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

Deep-subwavelength single grooves prepared by femtosecond laser direct writing on Si

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Chinese Physics B 2024年第8期33卷 108-115页

作者：叶瑞熙黄敏 State key laboratory of Optoelectronic materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China

It is well known that femtosecond laser pulses can easily spontaneously induce deep-subwavelength periodic surface structures on transparent dielectrics but not on non-transparent ***,in this study,we demonstrate that using high-numerical-aperture 800 nm femtosecond laser direct writing with controlled pulse energy and scanning speed in the near-damage-threshold regime,polarization-dependent deep-subwavelength single grooves with linewidths of~180 nm can be controllably prepared on ***,the single-groove linewidth increases slightly with increase in the pulse energy and decrease in the scanning speed,whereas the single-groove depth significantly increases from~300 nm to~600 nm with decrease in the scanning speed,or even to over 1μm with multi-processing,indicating the characteristics of transverse clamping and longitudinal growth of such deep-subwavelength single *** dispersive spectroscopy composition analysis of the near-groove region confirms that single-groove formation tends to be an ultrafast,non-thermal ablation process,and the oxidized deposits near the grooves are easy to clean ***,the results,showing both the strong dependence of groove orientation on laser polarization and the occurrence of double-groove structures due to the interference of pre-formed orthogonal grooves,indicate that the extraordinary field enhancement of strong polarization sensitivity in the deep-subwavelength groove plays an important role in single-groove growth with high stability and collimation.

关键词： femtosecond-laser direct writing of Si deep-subwavelength single grooves polarization dependence high numerical aperture ultrafast non-thermal ablation

Polarized imaging dynamic light scattering for simultaneous measurement of nanoparticle size and morphology

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Particuology 2024年第2期85卷 213-223页

作者： Bingyao Wang Tianyi Cai Xiaoshu Cai Wu Zhou Zeqi Liu Schoolof Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai200093China shanghai key laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093China Jiaxing MeaParTech Instrument Technology Co. LtdZhejiang314000China

The performance of nanoparticles is often affected by particle size and ***,electron microscopy or atomic force microscopy is typically utilized to determine the size and morphology of ***,there are issues such as difficult sample preparation,long processing times,and challenges in quantitative ***,it is of great significance to develop a fast,accu-rate,and statistical method to measure the size and morphology of *** this study,a new method,called polarized imaging dynamic light scattering(PIDLS),is *** nanoparticles are irradiated with a vertical linearly polarized laser beam,and a polarization camera collected the dynamic light scattering images of particles at four different polarization directions(0°,45°,90°,and 135°)at a scattering angle of 90°.The average particle size and distribution are obtained using the imaging dy-namic light scattering method at 0°polarization direction,and the morphology of the particles is ob-tained based on the depolarization patterns of the scattered *** optical sphericityΦis defined based on the degree of linear polarization(DoLP).It is also implemented for the quantitative evaluation of the sphericity of the nanoparticles,including spherical,octahedral,nanoplate,nanorod,and linear *** with the Poincarésphere parameterψ,the morphology of the nanoparticles can be roughly *** addition,PIDLS enables the measurement of particle size and morphology distributions simultaneously for evaluating the uniformity of *** effectiveness of PIDLS is verified by the measurement of five kinds of industrial titanium dioxide as well.

关键词： Imaging dynamic light scattering Polarized light scattering Non-spherical nanoparticles Morphology Online measurement

Specifications and control of spatial frequency errors of components in two-beam laser static holographic exposure for pulse compression grating fabrication

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High Power laser Science and Engineering 2024年第1期12卷 1-12页

作者： Chen Hu Songlin Wan Guochang Jiang Haojin Gu Yibin Zhang Yunxia Jin Shijie Liu Chengqiang Zhao Hongchao Cao Chaoyang Wei Jianda Shao Precision Optical Manufacturing and Testing Center Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences(CAS)ShanghaiChina key laboratory for High Power laser Material of Chinese Academy of Sciences Shanghai Institute of Optics and Fine MechanicsCASShanghaiChina Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhouChina China-Russian Belt and Road Joint laboratory on laser Science ShanghaiChina

The large-aperture pulse compression grating(PCG) is a critical component in generating an ultra-high-intensity, ultra-short-pulse laser;however, the size of the PCG manufactured by transmission holographic exposure is limited to large-scale high-quality materials. The reflective method is a potential way for solving the size limitation, but there is still no successful precedent due to the lack of scientific specifications and advanced processing technology of exposure mirrors. In this paper, an analytical model is developed to clarify the specifications of components, and advanced processing technology is adopted to control the spatial frequency errors. Hereafter, we have successfully fabricated a multilayer dielectric grating of 200 mm × 150 mm by using an off-axis reflective exposure system with Φ300 mm. This demonstration proves that PCGs can be manufactured by using the reflection holographic exposure method and shows the potential for manufacturing the meter-level gratings used in 100 petawatt class high-power lasers.

关键词： high-power laser off-axis reflective exposure system pulse compression grating spatial frequency errors specifications