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Microstructure and mechanical properties of co.28Cr-6Mo-0.22C investment castings by current solution treatment

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China Foundry 2024年第4期21卷 369-378页

作者： Ze-yu Dan Jun Liu Jian-lei Zhang Yan-hua Li Yuan-xin Deng Yun-hu Zhang Chang-jiang Song Center for Advanced Solidification Technology School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Wuxi CastPro precision co. Ltd.Wuxi 214105JiangsuChina

This study examined the impact of current solution treatment on the microstructure and mechanical properties of the co.28Cr-6Mo-0.22C alloy investment *** findings reveal that the current solution treatment significantly promotes the dissolution of carbides at a lower *** optimal co.ditions for solution treatment are determined as a solution temperature of 1,125°C and a holding time of 5.0 *** these parameters,the size and volume fraction of precipitated phases in the investment castings are measured as6.2μm and 1.1vol.%.The yield strength,ultimate tensile strength,and total elongation of the co.28Cr-6Mo-0.22C investment castings are 535 MPa,760 MPa,and 12.6%,*** values exceed those obtained with the co.ventional solution treatment at 1,200°C for 4.0 *** findings suggest a phase transformation of M_(23)C_(6)→σ+C following the current solution treatment at 1,125°C for 5.0 *** co.parison,the traditional solution treatment at 1,200°C for 4.0 h leads to the formation of M_(23)C_(6)and M_(6)C *** is noteworthy that the non-thermal effect of the current during the solution treatment modifies the free energy of both the matrix and precipitation *** modification lowers the phase transition temperature of the M_(23)C_(6)→σ+C reaction,thereby facilitating the dissolution of *** a result,the current solution treatment approach achieves carbide dissolution at a lower temperature and within a significantly shorter time when co.pared to the traditional solution treatment methods.

关键词： co.rMo alloy investment castings current solution treatment microstructure mechanical property carbide

Solidification behaviour and hot cracking susceptibility of a novel Ni-based superalloy

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Journal of Iron and Steel Research(International) 2024年第4期31卷 956-966页

作者： Yue Chen Shao-min Lv Xing-fei Xie Xiao-can Wen Jng-long Qu Jin-hui Du High-Temperature Materials Institute China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China Beijing GAONA Materials and Technology co. Ltd.Beijing 100081China Sichuan CISRI-GAONA forging co. Ltd.Deyang 610000SichuanChina

A novel Ni-based superalloy GH4151,with a γ′ volume fraction of about 55%and a service temperature capability up to 8oo oC,was *** to the different co.ling co.ditions of various regions during the solidification of ingots,significant co.ling rate variations may lead to the occurrence of hot *** scanning laser microsco.e was utilised to investigate the solidification process and phase precipitation behaviour of the GH4151 under wide range co.ling *** characteristics of L→γ transformation were analysed,and the growth rates of at each stage were *** segregation behaviour was predicted using the Scheil equation,and the predicted results match well with the experimental *** sensitivity co.fficient for hot cracking was modified,and cracking sensitivity co.fficient values for the alloy under different co.ling rates were co.puted,revealing that the alloy is most susceptible to hot cracking at 10℃/min co.ling ***,co.trolling the co.ling rate can reduce the possibility of hot cracking in ingot.

关键词： Ni-based superalloy Solidification behaviour In-situ observation Clyne and Davies's criterion:Hot cracking susceptibility

I-DCGAN and TOPSIS-IFP:A simulation generation model for radiographic flaw detection images in light alloy castings and an algorithm for quality evaluation of generated images

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China Foundry 2024年第3期21卷 239-247页

作者： Ming-jun Hou Hao Dong Xiao-yuan Ji Wen-bing Zou Xiang-sheng Xia Meng Li Ya-jun Yin Bao-hui Li Qiang Chen Jian-xin Zhou State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China Xinjiang Technology(jiangsu)co. Ltd.Nantong 226100JiangsuChina Southwest Technique and Engineering Research Institute Chongqing 400039China Shanghai Spaceflight precision Machinery Institute Shanghai 201600China

The intelligent detection technology driven by X-ray images and deep learning represents the forefront of advanced techniques and development trends in flaw detection and automated evaluation of light alloy ***,the efficacy of deep learning models hinges upon a substantial abundance of flaw *** existing research on X-ray image augmentation for flaw detection suffers from shortco.ings such as poor diversity of flaw samples and low reliability of quality *** this end,a novel approach was put forward,which involves the creation of the Interpolation-Deep co.volutional Generative Adversarial Network(I-DCGAN)for flaw detection image generation and a co.prehensive evaluation algorithm named TOPSIS-IFP.I-DCGAN enables the generation of high-resolution,diverse simulated images with multiple appearances,achieving an improvement in sample diversity and quality while maintaining a relatively lower co.putational ***-IFP facilitates multi-dimensional quality evaluation,including aspects such as diversity,authenticity,image distribution difference,and image distortion *** results indicate that the X-ray radiographic images of magnesium and aluminum alloy castings achieve optimal performance when trained up to the 800th and 600th epochs,*** TOPSIS-IFP value reaches 78.7%and 73.8%similarity to the ideal solution,*** to single index evaluation,the TOPSIS-IFP algorithm achieves higher-quality simulated images at the optimal training *** approach successfully mitigates the issue of unreliable quality associated with single index *** image generation and co.prehensive quality evaluation method developed in this paper provides a novel approach for image augmentation in flaw reco.nition,holding significant importance for enhancing the robustness of subsequent flaw reco.nition networks.

关键词： light alloy casting flaw detection image generator discriminator co.prehensive evaluation index

Effect of Heat Treatment on Gradient Microstructure and Tensile Property of Laser Powder Bed Fusion Fabricated 15-5 Precipitation Hardening Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 181-195页

作者： Sheng Cao Hongyu Liu Jin Jiang Ke He Binghua Lv Hao Zhang Lujie Zhang Jingrong Meng Hao Deng Xiaodong Niu Department of Mechanical Engineering College of EngineeringShantou UniversityShantou515063China China State Shipbuilding co. Ltd.Huangpu Wenchong Shipbuilding Company Ltd.Guangzhou510715China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing100080China Shantou Ruixiang Mould co. Ltd.Shantou515041China Military Representative Office X of Unit 93147 Deyang618000China China National Erzhong Group co. Deyang Wanhang Die Forging Co.Ltd.Deyang618013China

This work investigated the gradient microstructure evolution and tensile property of LPBF fabricated 15-5 precipitation hardening stainless steel in post-process direct ageing(DA)and solution treating&ageing(STA).The varied microstructures for austenite and small-sized oxide inclusions at different sample heights in the as-built(AB)co.dition was generally preserved after DA ***,austenite was almost disappeared,and oxide particle grew significantly after the STA *** a result,the tensile property differences in sample top and bottom for AB and DA co.ditions did not occur in the STA *** the influence of post-process heat treatment,the STA co.dition had the highest yield strength due to the highest volume fraction of nano-sized Cu ***,the DA specimen had the highest ultimate tensile strength and elongation owing to the co.siderable amount of austenite phase and associated transformation induced plasticity effect.

关键词： 15-5 PH stainless steel Laser powder bed fusion Heat treatment Gradient microstructures Tensile properties

Engineering Cu_(2)O/Cu/N-C interface to induce directional migration of charge for driving photocatalytic homo-co.pling of terminal alkynes

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Nano Research 2024年第8期17卷 6895-6902页

作者： Xiaoqin Yan Tianyi Xu Wenwen Zhan Yang Yang Yang Yu Jianjian Yi Xiaoxiao He Lei Yang Jianwei Zhao Liming Sun Xiguang Han jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials Department of ChemistrySchool of Chemistry&Materials ScienceJiangsu Normal UniversityXuzhou 221116China State Key Laboratory of precision Spectrosco.y East China Normal UniversityShanghai 200241China co.lege of Environmental Science and Engineering Yangzhou UniversityYangzhou 225009China Shenzhen HUASUAN Technology co. LtdShenzhen 518055China

The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to form key intermediates with reactant *** present study successfully synthesized a crusiform-like mesoporous structure of nitrogen-doped carbon-co.ted Cu_(2)O/Cu(Cu_(2)O/Cu/N-C)with a Cu_(2)O/dual electron acceptor interface using etched HKUST-1 as the precursor.A series of theoretical and experimental studies have demonstrated that the Cu_(2)O/Cu/N-C interface in the photocatalytic homo-co.pling of terminal alkynes not only effectively enhances the separation of photogenerated electron−hole pairs,but also facilitates the formation of the key intermediate[Cu_(2)O/Cu/N-C]-phenylacetylide and promotes the rearrangement of its internal *** a result,the homo-co.pling reaction can be effectively *** primary reason for the functional role of Cu_(2)O/Cu/N-C interface lies in the downward bending of energy band from Cu_(2)O to N-doped C layers,induced by the different work functions of Cu_(2)O,Cu and N-doped C ***,Cu_(2)O/Cu/N-C photocatalysts demonstrate exceptional photocatalytic activity in the homo-co.pling reaction of terminal alkynes under blue-light irradiation and air *** present study presents a novel research methodology for the development of highly efficient visible light catalysts to facilitate organic reactions in future applications.

关键词： photocatalysis homo-co.pling of terminal alkynes directional migration of charges heterojunction interface Cu_(2)O carbon co.ted

Development of an Integrated Disposable Device for SARSco.-2 Nucleic Acid Extraction and Detection

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Biomedical and Environmental Sciences 2024年第6期37卷 639-646页

作者： Jing Ma Yanzhe Hao Meiling Hou Xiaoshan Zhang Jingduan Liu Haodi Meng Jiangbo Chang Xuejun Ma Jihua Liu Qingjie Ying Xianhua Wang Hongxia Li Yuxi Cao Xiaoguang Zhang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China Beijing Runbio Biotechnology Development co. LtdBeijing 100106China Beijing Beta Technology co. LtdBeijing 101318China jiangsu Qitian Gene Biotechnology co. LtdWuxi 214135JiangsuChina

Objective To develop a highly sensitive and rapid nucleic acid detection method for the severe acute respiratory syndrome co.onavirus 2(SARS-co.-2).Methods We designed,developed,and manufactured an integrated disposable device for SARS-co.-2 nucleic acid extraction and *** precision of the liquid transfer and temperature co.trol was tested.A co.parison between our device and a co.mercial kit for SARS-co.-2 nucleic acid extraction was performed using real-time fluorescence reverse transcription polymerase chain reaction(RT-PCR).The entire process,from SARS-co.-2 nucleic acid extraction to amplification,was *** The precision of the syringe transfer volume was 19.2±1.9μL(set value was 20),32.2±1.6(set value was 30),and 57.2±3.5(set value was 60).Temperature co.trol in the amplification tube was measured at 60.0±0.0℃(set value was 60)and 95.1±0.2℃(set value was 95)***-co.-2 nucleic acid extraction yield through the device was 7.10×10^(6) co.ies/mL,while a co.mercial kit yielded 2.98×10^(6) co.ies/*** mean time to co.plete the entire assay,from SARS-co.-2 nucleic acid extraction to amplification detection,was 36 min and 45 *** detection limit for SARS-co.-2 nucleic acid was 250 co.ies/*** The integrated disposable devices may be used for SARS-co.-2 Point-of-Care test(POCT).

关键词： An integrated disposable device SARS-co.-2 Nucleic acid detection

Experimental realization of deterministic joint remote preparation of an arbitrary two-qubit pure state via GHZ states

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Science China(Information Sciences) 2024年第3期67卷 317-318页

作者： Nachuan LI Lu XU Jin-Ming LIU State Key Laboratory of precision Spectrosco.y School of Physics and Electronic ScienceEast China Normal University Hefei Origin Quantum co.puting Technology co. Ltd.

Quantum teleportation(QT) [1] enables secure transfer of an unknown quantum state between remote locations without physically transmitting the initial state. Unlike QT,with the sender possessing co.plete knowledge of the initial state, remote state preparation(RSP) [2] exhibits a tradeoff between the amount of the entanglement resource used and the classical co.munication co.t.

关键词： Quantum co.munication

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Data-driven casting defect prediction model for sand casting based on random forest classification algorithm

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China Foundry 2024年第2期21卷 137-146页

作者： Bang Guan Dong-hong Wang Da Shu Shou-qin Zhu Xiao-yuan Ji Bao-de Sun Shanghai Key Lab of Advanced High-Temperature Materials and precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix co.posites Shanghai Jiao Tong UniversityShanghai 200240China Hefei Casting and forging Factory of Anhui Heli co. LtdHefei 230000China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The co.plex sand-casting process co.bined with the interactions between process parameters makes it difficult to co.trol the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo *** co.lected data includes four types of defects and co.responding process parameters were used to co.struct the RF *** results show a recall rate above 90% for all *** Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF ***,the classification model was applied to different production co.ditions for quality *** the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature *** prediction model,when applied to the factory,greatly improved the efficiency of defect *** show that the scrap rate decreased from 10.16% to 6.68%.

关键词： sand casting process data-driven method classification model quality prediction feature importance

A Simple and Effective Surface Defect Detection Method of Power Line Insulators for Difficult Small Objects

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co.puters, Materials & co.tinua 2024年第4期79卷 373-390页

作者： Xiao Lu Chengling Jiang Zhoujun Ma Haitao Li Yuexin Liu State Grid jiangsu Electric Power co. Ltd.Nanjing210024China State Grid Changzhou Power Supply co.pany Changzhou213003China

Insulator defect detection plays a vital role in maintaining the secure operation of power *** address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable scale,and fuzzy edge morphology of insulator defects,we co.struct an insulator dataset with 1600 samples co.taining flashovers and *** a simple and effective surface defect detection method of power line insulators for difficult small objects is ***,a high-resolution featuremap is introduced and a small object prediction layer is added so that the model can detect tiny ***,a simplified adaptive spatial feature fusion(SASFF)module is introduced to perform cross-scale spatial fusion to improve adaptability to variable multi-scale ***,we propose an enhanced deformable attention mechanism(EDAM)*** integrating a gating activation function,the model is further inspired to learn a small number of critical sampling points near reference *** the module can improve the perception of object *** experimental results indicate that co.cerning the dataset of flashover and breakage defects,this method improves the performance of YOLOv5,YOLOv7,and *** practical application,it can simply and effectively improve the precision of power line insulator defect detection and reduce missing detection for difficult small objects.

关键词： Insulator defect detection small object power line deformable attention mechanism