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Effect of Vibrational Modes on Sand Pressure and Pattern Deformation in the EPC Process

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Journal of Materials Science & Technology 2004年第3期20卷 326-329页

作者： A.Ikenaga G.S.Cho k.H.Choe k.W.lee Department of Metallurgy and Materials Science Graduate School of EngineeringOsaka Prefecture University1-1 Gakuen-ChoSakaiOsaka 599-8531JapanAdvanced Material Processing TeamKorea Institute of Industrial Technology472KaJwa4-DongSeo-KuIncheon 404-264Advanced Material Processing TeamKorea Institute of Industrial Technology472KaJwa4-DongSeo-KuIncheon 404-264Advanced Material Processing TeamKorea Institute of Industrial Technology472KaJwa4-DongSeo-KuIncheon 404-264

During the EPC (expendable pattern casting) process, one of the essential requirements is to prevent pattern distortion duringsand filling and compaction. A new method which vibrates the system in a two-dimensional circular mode has been appliedto the EPC process. The molding properties of unbonded sand obtained by this new vibration mode are investigated andcompared with those in the one-dimensional vertical mode. For adequate compaction of sand. the circular vibration mode ismore effective than the vertical mode. Sand became more fluidized by the circular vibration and the particle pressure coefficientwas close to unity The particle pressure coefficient, which is defined as the ratio of horizontal to vertical sand pressure, isresponsible for the effectiveness of sand filling.

关键词： EPC process Sand compaction Vibration mode Pattern deformation Sand pressure

Effects of Alloying Elements on the Microstructures and Mechanical Properties of Heavy Section Ductile Cast Iron

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Journal of Materials Science & Technology 2007年第1期23卷 97-101页

作者： G.S.Cho k.H.Choe k.W.lee A.Ikenaga Advanced Material Processing Team Korea Institute of Industrial Technology994-32Dongchun-DongYeonsu-KuIncheon 406-130South Korea Department of Metallurgy and Materials Science Graduate School of EngineeringOsaka Prefecture University1-1Gakuen-ChoSakaiOsaka 599-8531Japan

The effects of alloying elements on the as-cast microstructures and mechanical properties of heavy section ductile cast iron were investigated to develop press die material having high strength and high ductility. Measurements of ultimate tensile strength, 0.2% proof strength, elongation and unnotched Charpy impact energy are presented as a function of alloy amounts within 0.25 to 0.75 wt pct range. Hardness is measured on the broken tensile specimens. The small additions of Mo, Cu, Ni and Cr changed the as-cast mechanical properties owing to the different as-cast matrix microstructures. The ferrite matrix of Mo and Ni alloyed cast iron exhibits low strength and hardness as well as high elongation and impact energy. The increase in Mo and Ni contents developed some fractions of pearlite structures near the austenite eutectic cell boundaries, which caused the elongation and impact energy to drop in a small range. Adding Cu and Cr elements rapidly changed the ferrite matrix into pearlite matrix, so strength and hardness were significantly increased. As more Mo and Cr were added, the size and fraction of primary carbides in the eutectic cell boundaries increased through the segregation of these elements into the intercellular boundaries.

关键词： Heavy section ductile cast iron Alloying elements As-cast microstructures As-cast mechanical properties

Effect of CaO addition on ignition behavior in molten AZ31 and AZ91D Magnesium alloys

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Rare Metals 2006年第Z2期25卷 155-159页

作者： lee Jin-kyu JO Hyung-Ho kIM Shae k. Department of Advanced Material Engineering Sungkyunkwan University 300 Chunchun-dong Jangan-gu Suwon Gyunggi-do 440-746 KoreaAdvanced Material Center Korea Institute of Industrial Technology 7-47 Songdo-dong Yeonsu-gu Incheon 406-840 Korea dvanced Material Center Korea Institute of Industrial Technology 7-47 Songdo-dong Yeonsu-gu Incheon 406-840 Korea

Mg alloys have been widely used in automobile and electronic industries because of high specific strength, good castability, etc. However, molten Mg alloys will burn rapidly in air if not protected. To solve this problem, the molten metal should be protected from oxidation by blanketing the surface with flux or protective gases. SF6 gas is widely used for Mg alloys as a cover gas and has proved to be a successful inhibitor. However, the use of SF6 gas is limited because of its high cost and its significant impact on non-global warming potential. Therefore, SF6 gas is being replaced by alternative protection gases. Recent studies show that there has been another attempt by adding CaO into Mg alloys. The aim of this study is to evaluate the effect of CaO on the minimum amount of protective gas, which is necessary not to make ignition in the molten AZ31 and AZ91 Mg alloys.

关键词： AZ91 AZ31 CaO clean production ignition resistance

Clawed Miniature Inchworm Robot Driven by Electromagnetic Oscillatory Actuator

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Journal of Bionic Engineering 2015年第4期12卷 519-526页

作者： kyung-min lee Youngshik kim Jamie k. Paik Buhyun Shin korean Intellectual Property Office Gov. Complex-Daejeon Bldg. 4 189 Cheongsa-ro Se-gu Daejeon 302-701 Korea Department of Mechanical Engineering Hanbat National University 125 Dongseodaero Yuseong-gu Daejeon 305-719 Korea The Institute of Mechanical Engineering EPFL STIlGM UPPAIK BM 4118 (B~timent BM) Station 17 Switzerland

In this research we propose a novel inchworm robot, which is composed of an Electromagnetic Oscillatory Actuator （EOA） and claws. The EOA consists of a yoke, a magnet, and a coil. The overall robot size is 12.2 mm x 11 mm x 9 mm （length x height ~ width）. The locomotion of the robot is achieved by different amounts of slips when the robot stretches and contracts its front leg. To realize locomotion, the working conditions were calculated theoretically and the calculated input signal was applied to the robot. The performance of the inchworm robot was evaluated experimentally with varying input voltages and frequencies. A simple op-amps based driving circuit was used to provide a square-wave input. Travel speed, average distance per step of the robot, and moving distance of the leg and body at each step were measured. The maximum travel speed was 36 mm-s-1 at 30 Hz, which validates our simple locomotion strategy experimentally.

关键词： electromagnetic actuator micro mobile robot inchworm crawler locomotion

An Integrated Die Casting Design System

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厦门大学学报（自然科学版） 2002年第S1期41卷 208-209页

作者： Y k Woon k S lee Dept. of Mechanical and Production Engineering National University of SingaporeDept. of Mechanical and Production Engineering National University of Singapore SingaporeSingapore

Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as cont

关键词： integrated die design system parametric design feature-based design

Multifunctional, Sustainable, and Biological Non-Ureolytic Self-Healing Systems for Cement-Based Materials

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Engineering 2022年第6期8卷 217-237页

作者： Mohammad Fahimizadeh Pooria Pasbakhsh lee Sui Mae Joash Ban lee Tan R.k.Singh Raman School of Engineering Monash University MalaysiaBandar Sunway 47500Malaysia School of Science Monash University MalaysiaBandar Sunway 47500Malaysia Tropical Medicine and Biology Multidisciplinary Platform Monash University MalaysiaBandar Sunway 47500Malaysia Department of Chemical Engineering&Department of Mechanical and Aerospace Engineering Monash UniversityClaytonVIC 3168Australia

Microbially induced calcium carbonate(CaCO_(3))precipitation(MICP)has been investigated as a sustain-able alternative to conventional concrete remediation methods for improving the mechanical properties and durability of concrete *** date,urea-dependent MICP is the most widely employed MICP pathway in biological self-healing concrete research as its use has resulted in efficient CaCO_(3) precipita-tion ***_(3) is a byproduct of ureolysis,and can be hazardous to cementitious structures and the health of various ***,non-ureolytic bacterial concrete self-healing systems have been developed as eco-friendly alternatives to urea-dependent self-healing ***-ureolytic pathways can improve the physical properties of concrete samples and incorporate the use of waste materials;they have the potential to be cost-effective and ***,they can be applied in terrestrial and marine *** date,research on non-ureolytic concrete self-healing systems has been scarce compared to that on ureolytic *** article discusses the advances and challenges in non-ureolytic bacterial concrete self-healing studies and highlights the directions for future research.

关键词： Self-healing concrete Mechanical properties Durability Non-ureolytic pathways Cement composite Sustainability

Properties of Dispersion Casting of Y2O3 Particles in Hypo,Hyper and Eutectic Binary Al-Cu Alloys

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Journal of Materials Science & Technology 2008年第1期24卷 57-59页

作者： J.J.Park G.H.kim S.M.Hong S.H.lee M.k.lee C.k.Rhee Nuclear Nano-Materials Development Lab. Korea Atomic Energy Research Institute （KAERI） 150 Deukjin-dongYuseong-gu Daejeon Korea

In the present work,the dispersion casting of Y-2O-3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 （hypo）,33 （eutectic） and 40 （hyper） wt pct by scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）.For the fabrication of Al-Cu alloy dispersed Y-2O-3 ceramic particles,stir casting method was *** case of Al-20 wt pct Cu alloy （hypoeutectic）,SEM images revealed that primary Al was grown up in the *** that,eutectic phase with well dispersed ceramic particles was *** case of eutectic composition,Y-2O-3 particles were uniformly dispersed in the *** the Cu is added into Al up to 40 wt pct （hypereutectic）,primary phase was grown up without any Y-2O-3 ceramic particles in the early stage of ***, eutectic phase was formed with well dispersed ceramic *** can be concluded that Y-2O-3 ceramic particles is mostly dispersed in case of eutectic composition in Al-Cu alloy.

关键词： Dispersion casting Y2O3 particles Stir casting Al-Cu alloy

Fe-Ti oxide and Fe-Cu sulfide exsolution in amphibole cumulate xenoliths from granodiorite in Tongling,Anhui Province

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Chinese Science Bulletin 2003年第23期48卷 2626-2634页

作者： QINXinlong DUYangsong H.k.lee YINJingwu GUOXifeng EducationMinistrykeyLaboratoryofLithosphereTectonicsandExplorationTechnology ChinaUniversityofGeosciencesBeijing100083China DepartmentofGeology CollegeofNaturalSciencesChungnamNationalUniversityTaejon305-764RepublicofKorea

A number of Fe-Ti oxide and Fe-Cu sulfide exsolution phases are found in amphibole cumulate xenoliths from Mesozoic granodioritic plutons at Jiguanshi and Jin- kouling in Tongling, Anhui Province. Most of amphiboles in the xenoliths have been identified as pargasite, and deter-mined as a crystallization phase in the lower crust. The oxide exsolutions commonly acicular, are distributed parallel to [100] of amphibole with a typical Schiller texture. They con-tain 0.29%—51.07% of TiO2, and correspond to magnetite, titaniferous magnetite, titanomagnetite or ilmenite. All ex-solved sulfide grains, being rounded to extended rounded in shape, are regularly arranged in sub-paralleled or closely beaded groups, except for a few of grains that are scattered or isolated. The exsolved sulfide phases comprise mostly pyrrhotite, secondarily cubanite and chalcopyrite, and rarely pyrite. A few grains of magnetite can coexist with pyrrhotite in most samples. The sulfide phases are poor in nickel (usu-ally Ni < 0.5%, Ni/Fe < 0.003), while relative enrichments in copper (up to 2.93%) typify the pyrrhotite. Additionally, both oxides and sulfides may be exsolved in the same area of amphibole. Occurrence of Fe-Ti oxide and Fe-Cu sulfide exsolution phases in the xenoliths leads to inference that ore-forming materials such as S, Fe, Cu, etc. have been pri-marily dissolved in Mesozoic magma within the lower crust beneath the Tongling area.

关键词：闪石捕虏岩花岗闪长岩安徽 Fe-Ti氧化物 Fe-Cu硫化物

New insights into carbon-based and MXene anodes for Na and k-ion storage: A review

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Journal of Energy Chemistry 2021年第11期30卷 660-691,I0016页

作者： Zhensheng Hong Hajar Maleki Tim Ludwig Yichao Zhen michael Wilhelm Damin lee kwang-Ho kim Sanjay Mathur Fujian Provincial key Laboratory of Quantum Manipulation and New Energy Materials College of Physics and EnergyFujian Normal UniversityFuzhou 350117FujianChina Institute of Inorganic Chemistry University of CologneGreinstr.650939 CologneGermany Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering Fuzhou 350117FujianChina Global Frontiers of Hybrid Interfacial Materials Pusan National UniversitySouth Korea

Na-ion batteries and k-ion batteries are promising alternatives to vastly used lithium-ion batteries mainly due to the larger natural abundance of sodium and potassium resources. Carbon-based and MXene materials have received increasing attention due to their unique layered structure to accommodate the larger sodium and potassium ions. It’s proposed that ionic size disparity (k^(+): 1.38 Å;Na^(+): 0.97 Å;Li^(+): 0.76 Å) leads to sluggish intercalation and extraction kinetics in larger alkali metal ions (AMIs). Nevertheless, the electrochemical inactivity of sodium intercalation in graphite suggests that different chemical properties of AMs and their interactions with carbon host and electrolytes is crucial for interfacial instability and irreversible capacity loss. Structural modifications by expanding interlayer spacing and defect engineering enable reduced diffusion barriers and enhanced insertion of sodium or potassium, but it blurs the electrochemical performance between battery and capacitor. This review provides insight into 2D carbon materials and their architectures for Na and k-ion batteries through an in-depth analysis of structure–property interdependence and different electrochemical mechanisms supported by both experimental and theoretical data to discuss the promises and challenges of post-lithium batteries. Finally, the perspectives and potential directions regarding material design concepts for 2D carbon-based nanomaterials and MXene phases for metal-ion storage are proposed.

关键词： Na-ion batteries k-ion batteries Anode Carbon materials Structure design