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Cracking Susceptibility After Post-Weld Heat Treatment in Haynes 282 Nickel Based Superalloy

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Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 747-753页

作者： L.O.Osoba A.K.Khan S.O.Adeosun department of metallurgical and materials engineering University of Lagos department of Mechanical and Manufacturing engineering University of Manitoba

This paper presents a study of the standard post-weld heat treatment （PWHT） behaviour of autogenous laser welded γ＇ age-hardenable precipitation strengthened nickel based superalloy Haynes 282 （HY 282）. The study involves a careful and detailed microstructural characterisation as well as an analysis of the weld cracking susceptibility during welding and Gleeble thermo-mechanical physical simulation. Various factors that could influence post-weld cracking in superalloys weld were experimentally examined. Our microstructural exami- nation of the as-solution heat treated （SHTed） material and the thermo-mechanically refined grain material shows that intergranular heat affected zone （HAZ） cracking is observable in only the as-welded SHTed material. There was no indication of post-weld heat treatment cracking in all welded materials. Our conclusion, in this study, is that the chemistry of superalloy HY 282 which aids the preclusion/formation of deleterious so- lidification microconstituents during welding as well as its relatively slow aging kinetics enhances its resistance to PWHT cracking.

关键词： Cracking Microstructure Analysis Nickel based Superalloy

Comparison of effective parameters for copper powder production via electrorefining and electrowinning cells and improvement using DOE methods

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International Journal of Minerals,Metallurgy and materials 2011年第6期18卷 731-740页

作者： Ebrahim Akbarzadeh Sayyed Esmaeil Shakib department of materials Science and metallurgical engineering Shahid Bahonar University of Kerman

The influences of cupric ion concentration （5-35 g/L）,current density （500-2000 A/m2）,circulation rate of the electrolyte solution （15-120 mL/min）,and temperature （25-60℃） on the physical and chemical properties of copper powders obtained in electrolysis cells were *** industrial processes,electrorefining （ER） cells with a synthetic electrolyte and electrowinning （EW） cells with an original solution of coppermineral leaching,were utilized to produce copper ***,the statistical full factorial method of design of experiments （DOE） was employed to investigate the interaction or the main effects of *** results show that increasing the copper concentration and temperature can increase the grain size,apparent density,and electrical energy *** the other hand,increasing the current density and circulation rate of the electrolyte can decrease *** production process is optimized via DOE to control the interactive and main effects to produce copper powders with favorable properties.

关键词： copper powders electrorefining electrowinning grain size apparent density

Utilization of waste polyethylene terephthalate as a reducing agent in the reduction of iron ore composite pellets

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International Journal of Minerals,Metallurgy and materials 2014年第8期21卷 748-754页

作者： Gkhan Polat Burak Birol Muhlis Nezihi Saridede department of metallurgical and materials engineering Yildiz Technical University Istanbul Turkey

The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate （PET）, because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450℃ for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron （iron nuggets） were reduction at 1450℃ for 10 min using composite pellets containing 60% PET and 40% coke.

关键词： polyethylene terephthalate (PET) waste recycling reducing agents iron ore pellets ore reduction

Endoscopy-assisted lightweight diagnosis system based on transformers for colon polyp detection

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Optoelectronics Letters 2025年第1期21卷 57-64页

作者： FAN Weiming YU Jiahui JU Zhaojie School of Automation and Electrical engineering Shenyang Ligong University department of Biomedical engineering Zhejiang University School of Computing University of Portsmouth

The integration of endoscopy has significantly propelled the diagnosis and treatment of gastrointestinal diseases, with colonoscopy establishing itself as the primary method for early diagnosis and preventive care in colorectal cancer(CRC). Although deep learning holds promise in mitigating missed polyp rates, modern endoscopy examinations pose additional challenges, such as image blurring and atomizing. This study explores lightweight yet powerful attention mechanisms, introducing the spatial-channel transformer(SCT), an innovative approach that leverages spatial channel relationships for attention weight calculation. The method utilizes rotation operations for inter-dimensional dependencies, followed by residual transformation, encoding inter-channel and spatial information with minimal computational overhead. Extensive experiments on the CVC-Clinic DB polyp detection dataset, addressing endoscopy pitfalls, underscore the superiority of our SCT over other state-of-the-art methods. The proposed model maintains high performance, even in challenging scenarios.

关键词： Endoscopy

Effect of grain refinement on phase transformation behavior and mechanical properties of Cu-based alloy

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中国有色金属学会会刊：英文版 2009年第4期19卷 979-983页

作者： Gwon-Seung YANG Jong-Kook LEE Woo-Yang JANG department of Advanced materials engineering Chosun University department of metallurgical engineering Chosun University

A small amount of misch metal was added to Cu-Zn-Al alloy in order to study its effect on grain refinement,mechanical properties,phase transformation behavior and stabilization of *** is found that the addition of misch metal is very effective for reducing the grain *** coarse grains over 1 000 μm are refined to the size of 30 μm by the addition of 0.43%(mass fraction) misch *** grain size of thermo-mechanically treated alloys is barely affected by cold *** fracture strength and ductility increase significantly with the increase of misch metal content when tensile test is carried out below Mf ***,the fracture strength is larger in the case of post-quench ageing treatment than that in the case of direct quench ageing *** fracture mode is changed from transgranular brittle fracture to ductile fracture with void formation and coalescence by the addition of misch metal.

关键词：铜基合金力学性能相变行为晶粒细化金属拉伸试验晶粒尺寸断裂强度时效处理

Characterization of Cu–Ti powder metallurgical materials

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International Journal of Minerals,Metallurgy and materials 2017年第1期24卷 83-90页

作者： Erdem Karakulak metallurgical and materials engineering department Kocaeli UniversityKocaeli 41380Turkey

Powder metallurgical Cu-Ti alloys with different titanium additions produced by hot pressing were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and hardness, wear and bending tests. The addition of titanium to copper caused the formation of different intermetallic layers around titanium particles. The titanium content of the intermetallics decreased from the center of the particle to the copper matrix. The hardness, wear resistance, and bending strength of the materials increased with increasing Ti content, whereas strain in the bending test decreased. Worn surface analyses showed that different wear mechanisms were active during the wear test of specimens with different chemical compositions. Changes in the properties of the materials with titanium addition were explained by the high hardness of different Cu-Ti intermetallic phases.

关键词： copper titanium alloys powder metallurgy sintering mechanical properties wear

Investigation on the homogenization treatment and element segregation on the microstructure of a γ/γ′-cobalt-based superalloy

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International Journal of Minerals,Metallurgy and materials 2019年第2期26卷 222-233页

作者： Saeed Aliakbari Sani Hossein Arabi Shahram Kheirandish Golamreza Ebrahimi School of materials and metallurgical engineering Iran University of Science and Technology ((IUST)) School of materials and metallurgical engineering Iran University of Science and Technology (IUST) materials and Polymers engineering department Faculty of Engineering Hakim Sabzevari University

The aim of the present study was to investigate the effect of element segregation on the microstructure and γ′ phase in a γ/γ′ cobalt-based superalloy. Several samples were prepared from a cast alloy and homogenized at 1300°C for different times, with a maximum of 24 h. A microstructural study of the cast alloy using wavelength-dispersive spectroscopic analysis revealed that elements such as Al, Ti, and Ni segregated mostly within interdendritic regions, whereas W atoms were segregated within dendrite cores. With an increase in homogenization time, segregation decreased and the initial dendritic structure was eliminated. Field-emission scanning electron microscopy micrographs showed that the γ′ phases in the cores and interdendritic regions of the as-cast alloy were 392 and 124 nm, respectively. The size difference of γ′ was found to be due to the different segregation behaviors of constituent elements during solidification. After homogenization, particularly after 16 h, segregation decreased; thus, the size, chemical composition, and hardness of the precipitated γ′ phase was mostly uniform throughout the samples.

关键词： superalloy segregation homogenization microstructure γ′phase

Boosting aqueous nickel-zinc battery stability with bimetallic ion-integrated 1D metal-organic nanowires

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Science China Chemistry 2025年

作者： Yihao Chen Jin Liang Yichun Su Guoyin Zhu Hengyue Xu Hongye Ding Guangxun Zhang Dianheng Yu Zizhou Shen Yizhou Zhang Wei Huang Huan Pang School of Chemistry and Chemical engineering Yangzhou University Key Laboratory of Flexible Electronics (KLoFE) & Institute of Advanced materials (IAM) School of Flexible Electronics (Future Technologies) Nanjing Tech University (NanjingTech) Institute of Advanced materials and Flexible Electronics (IAMFE) School of Chemistry and Materials Science Nanjing University of Information Science & Technology department of Chemistry Tsinghua University State Key Laboratory of Coordination Chemistry Nanjing University

Limited by low conductivity,designing cathode materials with excellent electron transfer efficiency for high-performance nickel-zinc batteries （NZBs） remains *** this study,a series of bimetallic metal-organic nanowires were fabricated by doping M ions in NiNTA,resulting in NiMNTA (M=Mg2+,Mn2+,Co2+,Zn2+,Ag+),and NixCo6-xNTA （x=1,2,3,4,5）.The proportions and types of metal ions can be modified without altering the initial coordination structure.X-ray absorption fine structure spectroscopy （XAFS） revealed that only M–O bonds,not metal bonds,were present in the *** performance of Ni2Co4NTA as the cathode for aqueous NZBs was significantly improved,achieving the maximum energy density of 279.17Wh kg-1with the high cycle stability （retention rate of 72.0%after 1,000 cycles）.The flexible Ni2Co4NTA//Zn@carbon cloth battery employing gel electrolyte also exhibits the excellent Coulombic efficiency of 96%after 350 *** approach shows considerable potential for designing one-dimensional materials with bimetallic modifications,providing new strategies for developing cathode materials for NZBs with high specific capacity and cycle stability.

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“One stone, two birds”: Salt template enabling porosity engineering and single metal atom coordinating toward high-performance zinc-ion capacitors

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Journal of Energy Chemistry 2025年第1期 637-645页

作者： Chunliu Zhu Huanyu Liang Ping Li Chenglong Qiu Jingyi Wu Jingwei Chen Weiqian Tian Yue Zhu Zhi Li Huanlei Wang School of materials Science and engineering Ocean University of China department of Chemical and materials engineering University of Alberta

Zinc-ion hybrid capacitors （ZIHCs） have received increasing attention as energy storage devices owing to their low cost,high safety,and environmental ***,their progress has been hampered by low energy and power density,as well as unsatisfactory long-cycle stability,mainly due to the lack of suitable electrode *** this context,we have developed manganese single atoms implanted in nitrogen-doped porous carbon nanosheets （MnSAs/NCNs） using a metal salt template method as cathodes for *** metal salt serves a dual purpose in the synthesis process:It facilitates the uniform dispersion of Mn atoms within the carbon matrix and acts as an activating agent to create the porous *** applied in ZIHCs,the MnSAs/NCNs electrode demonstrates exceptional performance,including a high capacity of 203 m Ah g-1,an energy density of 138 Wh kg-1at 68 W kg-1,and excellent cycle stability with 91%retention over 10,000 *** calculations indicate that the introduced Mn atoms modulate the local charge distribution of carbon materials,thereby improving the electrochemical *** work demonstrates the significant potential of carbon materials with metal atoms in zinc-ion hybrid capacitors,not only in enhancing electrochemical performance but also in providing new insights and methods for developing high-performance energy storage devices.

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