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MATERIALS TRANSACTIONS Vol. 51 (2010), No. 8

ISIJ International
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ONLINE ISSN: 1347-5320
PRINT ISSN: 1345-9678
Publisher: The Japan Institute of Metals and Materials

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MATERIALS TRANSACTIONS Vol. 51 (2010), No. 8

The Assimilation Mechanism of Mn-Al Compacts in Liquid Mg

Zhi Li, Stavros A. Argyropoulos

pp. 1371-1380

Abstract

This paper describes the assimilation mechanism of Mn-Al compacts in liquid Mg, utilizing procedures that have been employed successfully in studying assimilation mechanisms in other liquid metals. Two critical steps were identified in the assimilation process: (1) melting of some Mn-Al reaction products and (2) mass transfer of phases with the high Mn content from the reaction sites into the Mg bath. The assimilation process was divided into three stages: incubation stage, intermetallic reaction stage, and homogenization stage. Compact swelling was observed during the intermetallic reaction stage. Yet, contrary to the currently-held prevalent view, it was determined that compact swelling was not due primarily to the formation of new intermetallic phases. Rather, swelling is due to the existence of a large amount of porosity initially in the compact which becomes greatly augmented with the large heat released during the Mn-Al exothermic intermetallic reactions.

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The Assimilation Mechanism of Mn-Al Compacts in Liquid Mg

Atomic-Scale Characterization of Elastic Deformation of Zr-Based Metallic Glass under Tensile Stress

Shigeo Sato, Hiroshi Suzuki, Takahisa Shobu, Muneyuki Imafuku, Yoshinori Tsuchiya, Kazuaki Wagatsuma, Hidemi Kato, Albertus Deny Setyawan, Junji Saida

pp. 1381-1385

Abstract

In-situ observation of elastic deformation behaviors of Zr55Al10Ni5Cu30 bulk metallic glass under tensile stress was carried out using the high-energy X-ray scattering method. Two analytical procedures—the reciprocal-space method and direct-space method—were applied. The reciprocal-space method, used for the estimation of an apparent atomic spacing, can evaluate the strain in the range of several nanometers. We found that this method yields a large Young’s modulus (115 GPa) and a small Poisson’s ratio (0.32), as compared to the macroscopic values of 101 GPa and 0.38, respectively. Thus, the macroscopic deformation is larger than the microscopic deformation characterized by the X-ray scattering method. This feature indicates the possibility of inhomogeneous regions with weakly bonded structures existing locally in the glassy structure and acting as significant deformation sites in the elastic stage. The direct-space method suggests that the Zr-Zr nearest pair has a higher sensitivity to an applied stress than the Zr-Cu pair. Moreover, both the nearest pairs in the first shell (r<0.4 nm) exhibit a slight distortion, as compared with the deformation observed in the second or higher coordination shell (r>0.4 nm). We explain this deformability gap with the hypothesis that the free volume in the first coordination shell assists the glide of atoms. This results in a larger strain in the second or higher coordination shell than in the first shell.

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Atomic-Scale Characterization of Elastic Deformation of Zr-Based Metallic Glass under Tensile Stress

Effect of Reaction Driving Force on Copper Nanoparticle Preparation by Aqueous Solution Reduction Method

Qingming Liu, Debi Zhou, Kazuaki Nishio, Ryoichi Ichino, Masazumi Okido

pp. 1386-1389

Abstract

Copper nanoparticle was prepared by aqueous solution reduction method. Cu2+ was reduced to a copper particle by using different types of reductants named ascorbic acid (C6H8O6), phosphinic acid (H3PO2), titanium sulfate (Ti2(SO4)3) and sodium borohydride (NaBH4). The effect of reaction driving force on the average size of copper particles was investigated. An inversely proportional relationship between the reaction driving force and the average size of copper particles was found, wherein the average size of copper particles decreases as the reaction driving force increases.

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Effect of Reaction Driving Force on Copper Nanoparticle Preparation by Aqueous Solution Reduction Method

Effect of Electropulsing on Recrystallization of Fe-3%Si Alloy Strip

Guoliang Hu, Chanhung Shek, Yaohua Zhu, Guoyi Tang, Xu Qing

pp. 1390-1394

Abstract

Recrystallization and microstructural changes of an electropulsing treated (EPT) Fe-3%Si alloy strip were studied using optical microscopy and electron backscattering diffraction (EBSD) techniques. Microstructural evolution and misorientation angle distribution were detected during recrystallization in both EPT and traditional heat treated (THT) alloy specimens. The results indicate electropulsing tremendously accelerated movement of dislocation and vacancies, which is in favors of recrystallization. The temperature of recrystallization was reduced. A sufficient high temperature became a dominant factor in speeding up recrystallization. The mechanism of electropulsing induced recrystallization is discussed from the point view of dislocation dynamics, microstructural changes and electropulsing kinetics.

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Effect of Electropulsing on Recrystallization of Fe-3%Si Alloy Strip

Effect of Nb and Ti Addition on Microstructure and Hardness of Dual Two-Phase Intermetallic Alloys Based on Ni3Al-Ni3V Pseudo-Binary Alloy System

K. Kawahara, T. Moronaga, Y. Kaneno, A. Kakitsuji, T. Takasugi

pp. 1395-1403

Abstract

The microstructures and hardness property of dual two-phase intermetallic alloys that are composed of various kind of volume fractions of geometrically closed packed (GCP) Ni3Al(L12) and Ni3V(D022) phases was studied. Higher volume fraction of primary Ni3Al precipitates was observed in the Ti and Nb added alloys when keeping Al content the same. Also, the microstructures in the eutectoid (channel) region consisting of Ni3Al+Ni3V were sensitive to alloying addition. The hardness of dual two-phase intermetallic alloys was basically explained by mixture rule in hardness between primary Ni3Al precipitates and eutectoid region. Nb and Ti addition raised hardness of dual two-phase intermetallic alloys by solid solution hardening in the constituent phases. This hardening was more significant in Nb addition than in Ti addition. In addition to hardness owing to the mixture rule, additional hardening arising from interfacial area between primary Ni3Al precipitates and eutectoid region was found. With increasing Ni3Al/channel (eutectoid) interfacial area, the additional hardening increased. As temperature increases, the additional hardening monotonously decreased for the base and Nb added alloys but little decreased for the Ti added alloys.

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Effect of Nb and Ti Addition on Microstructure and Hardness of Dual Two-Phase Intermetallic Alloys Based on Ni3Al-Ni3V Pseudo-Binary Alloy System

Fatigue Process Evaluation of Ultrasonic Fatigue Testing in High Strength Steel Analyzed by Acoustic Emission and Non-Linear Ultrasonic

Mitsuharu Shiwa, Yoshiyuki Furuya, Hisashi Yamawaki, Kaita Ito, Manabu Enoki

pp. 1404-1408

Abstract

Non-linear ultrasonic and acoustic emission (AE) signals during ultrasonic fatigue testing were analyzed by using Laser Doppler Vibrometer (LDV) and continuous AE waveform analysis system (1 MHz/12 bit). Notched specimens of a high strength low alloy steel were prepared for the ultrasonic fatigue test with exciting vibration frequency of 20 kHz. The detected surface velocity was longitudinal direction at the end of specimen with frequency range from 200 Hz to 500 kHz. During the waveform monitoring of the fatigue test, a distorted exciting waveform was observed in final stage of the test. Then the burst type noise mixed with the distorted exciting waveform was obtained just before the final failure in the case of failure specimens. Contrary, the distorted exciting waveform and AE were not observed in the case of non-failure specimens. AE signal and upper harmonics of exciting frequency were analyzed by the FFT method. As the result, after the intensity of 2nd and 3rd harmonics increased rapidly, AE events were detected continuously in the case of failure specimens. It can be concluded that nonlinear ultrasonic and AE analysis were effective monitoring tool for fatigue damage progression.

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Fatigue Process Evaluation of Ultrasonic Fatigue Testing in High Strength Steel Analyzed by Acoustic Emission and Non-Linear Ultrasonic

SCC Monitoring of Chloride Droplets on Thin SUS304 Plate Specimens by Analysis of Continuous Recorded AE Waveform

Kaita Ito, Hisashi Yamawaki, Hiroyuki Masuda, Mitsuharu Shiwa, Manabu Enoki

pp. 1409-1413

Abstract

An acoustic emission (AE) monitoring method for chloride stress corrosion cracking (SCC) in SUS304 stainless steel has been proposed to investigate this mechanism. The method combines a droplet SCC monitoring system and an AE system capable of continuous waveform data acquisition and storage. MgCl2 droplets were placed on a thin plate specimen of SUS304 to induce SCC. Since detected AE waveforms had small amplitudes with large noises, a means of noise filtering was developed to extract these features, based on time-frequency analysis of the continuous waveform. About 200 AE events were taken out after filtering. SEM observation showed that the AE source was attributable to transgranular SCC which cannot be detected by conventional AE monitoring systems. Therefore the new method demonstrated high sensitivity for the SCC monitoring.

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SCC Monitoring of Chloride Droplets on Thin SUS304 Plate Specimens by Analysis of Continuous Recorded AE Waveform

Checking Surface Contamination and Determination of Electrical Resistivity of Oxide Scale Deposited on Low Carbon Steel by DC Potential Drop Method

Md. Rostom Ali, Masumi Saka, Hironori Tohmyoh

pp. 1414-1419

Abstract

This article describes about the nature of potential drops (PDs) on carbon steel (SS400) and stainless steel (SUS304). The experimental results showed the remarkable nature of potential drops on oxidized surface. Direct current PD (DCPD) technique was used to investigate the nature of potential drops on the test surfaces with probe contact time. The nature of PDs on oxidized and oxide scale free surfaces were compared for the same experimental conditions and it is easy to compare the contaminated surface with oxide scale free surface and to decide whether the surface is oxidized or clean. Oxidized test surface is considered as two layers of different resistivities. The effect of two layers on the potential drops was illuminated by electrical image method. Electrical resistivity of oxide scale was determined by DCPD technique on the basis of the two layers of different resistivities model. In an attempt to verify the accuracy and prove the validity of the proposed method, the electrical resistivity is also determined at different probe spacing and all the results are shown to be very proximate to one another.

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Checking Surface Contamination and Determination of Electrical Resistivity of Oxide Scale Deposited on Low Carbon Steel by DC Potential Drop Method

Shell Mold Cracking and Its Prediction during Casting of AC4C Aluminum Alloy

Shuxin Dong, Yasushi Iwata, Hiroshi Hohjo, Hiroaki Iwahori, Takashi Yamashita, Haruyoshi Hirano

pp. 1420-1427

Abstract

The mechanism of shell mold cracking and its prediction during casting of aluminum alloy were elucidated. A cylindrical shell mold made of silica sand fractures easily when filled with aluminum alloy melt. The cracking mechanism can be considered as follows. The immediate inner surface of a shell mold undergoes a sudden temperature rise from heating by the melt and attempts to expand. This thermal expansion is restrained by the other part of the mold that is still low in temperature. Consequently, compressive stress in the area near the inner surface and tensile stress in the area near the outer surface develop respectively, causing the shell mold to fracture when the tensile stress exceeds the tensile strength of the shell mold. With some part of a cylindrical shell mold cut to a thinner thickness, a higher tensile stress acts on the outer surface of the thinner part and a crack is formed in a shorter time after the mold has been filled with aluminum alloy melt. The criterion for shell mold cracking can be described by the relation of fracture stress and effective volume based on the Weibull’s statistical method, which is utilized for evaluating the strength of brittle materials. The relation of fracture stress and effective volume enabling us to predict the shell mold cracking was obtained from the statistical properties of the tensile strength of the shell mold material.

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Shell Mold Cracking and Its Prediction during Casting of AC4C Aluminum Alloy

Microstructures and Mechanical Properties of (Ti0.8Mo0.2)C-30 mass% Ni without Core-Rim Structure

Hiroyuki Hosokawa, Kiyotaka Kato, Koji Shimojima, Akihiro Matsumoto

pp. 1428-1432

Abstract

Mechanically alloyed powders having the composition (Ti0.8Mo0.2)C-30 mass% Ni were sintered at 1723 K for 2, 3, and 6 h. After sintering, a TiC phase without a core-rim structure and a Ni phase appeared. In addition, the X-ray diffraction spectrum of 6 h sintered compact showed a Mo peak. With an increase in the sintering time, the hard phase grain size, mean free path of the binder phase, and the binder phase volume fraction increased. The transverse rupture strength and Vickers hardness of the sintered compacts were measured. The maximum average transverse rupture strength was 1.51 GPa for 3-h sintered compact. The relationship between the hardness and the microstructure could be explained by the composite law including the structural factors. 2-h sintered compact had the highest hardness because of the relatively short mean free path of binder phase. 6-h sintered compact had the largest grain size, lowest volume fraction of the hard phase, and the longest mean free path of binder phase. However, this compact was harder than 3-h sintered compact because of the significantly high hard phase contiguity.

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Microstructures and Mechanical Properties of (Ti0.8Mo0.2)C-30 mass% Ni without Core-Rim Structure

Laser Direct Joining of Glassy Metal Zr55Al10Ni5Cu30 to Engineering Plastic Polyethylene Terephthalate

Yousuke Kawahito, Yusuke Niwa, Takeshi Terajima, Seiji Katayama

pp. 1433-1436

Abstract

Metals and plastics are widely used in industrial applications, and glassy metals are recently receiving a considerable attention in terms of high strength and great corrosion resistance. Joining of a metal or glassy metal to a plastic is necessary and important in manufacturing high performance products. Therefore, we have developed laser-assisted metal and plastic (LAMP) joining as an innovative rapid bonding process without adhesives or glues. In this research, therefore, LAMP joining was applied to bond Zr55Al10Ni5Cu30 metallic glass sheet and polyethylene terephthalate (PET) plate. The LAMP joint exhibited the same strength as the base glassy metal. According to the results of X-ray diffraction (XRD) and diffraction patterns of transmission electron microscope (TEM), samples were confirmed to be still amorphous. Moreover, TEM photos and energy dispersive X-ray spectroscopy (EDS) analysis demonstrated that the glassy metal and the plastic were tightly bonded on the atomic or molecular size level through zirconium oxide film covering glassy metal. Consequently, it was revealed that a Zr55Al10Ni5Cu30 metallic glass sheet was directly joined onto an engineering plastic PET plate and kept amorphous phase of the metallic glass after the LAMP joining.

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Laser Direct Joining of Glassy Metal Zr55Al10Ni5Cu30 to Engineering Plastic Polyethylene Terephthalate

High Electric Conductive PMMA Composites without Impact Value Decay by Dispersion of Copper Powder

Yoshitake Nishi, Yoshihide Ebihara, Nobuhiro Kunikyoh, Masae Kanda, Keisuke Iwata, Kaori Yuse, Benoit Guiffard, Laurent Lebrun, Daniel Guyomar

pp. 1437-1442

Abstract

Copper powder dispersed poly-methyl methacrylic acid (acrylic resin, PMMA) composites (PMMA-Cu) were prepared by the solution cast method. The Cu addition at the critical volume fraction (15.0±1.0 vol%Cu) drastically enhanced the electric conductivity from the insulator (10−14 Sm−1) to the electric conductor (105 Sm−1). The electric conductivity can be obtained by controlling the volume fraction of copper powders in PMMA polymers, as dilatation. The addition of 10 vol%Cu slightly enhanced the impact value of PMMA, whereas the remarkable decrease in the Charpy impact value was found at 25±5 vol%Cu. The high conductive PMMA-Cu composites (from 15 to 20 vol%Cu) with high impact value (5.5±0.5 kJm−2), which was higher than that of dispersed nylon6 composites (2 kJm−2) utilized for practical exteriors, were obtained without impact value decay by addition of small amount of copper powders.

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High Electric Conductive PMMA Composites without Impact Value Decay by Dispersion of Copper Powder

Photocatalytic Activities and Crystal Structures of Titanium Dioxide by Anodization: Their Dependence upon Current Density

Yoshiteru Mizukoshi, Naoya Masahashi

pp. 1443-1448

Abstract

The crystal structure, crystallinity and surface area of anodized TiO2 were systematically investigated focusing on the current density in the anodization. Anatase phase was evolved with an increase of the current density for the anodic oxides prepared in the electrolyte of 0.1 mol·L−1 sulfuric acid, and the surface area was almost constant against the current density. On the other hand, rutile phase was evolved with the same of 1.2 mol·L−1 sulfuric acid, and the surface area increased with the current density. Photocatalytic degradation rates of methylene blue (MB) were normalized by surface area of TiO2, showing that the maximum value was found in the anodic oxide with approximately 60% of rutile in the fraction. The specific rate constant for MB degradation was the best in the anodic oxide with low lattice strain and the crystallite size of appropriately 40 nm.

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Photocatalytic Activities and Crystal Structures of Titanium Dioxide by Anodization: Their Dependence upon Current Density

Fabrication and Mechanical Properties of Porous Ti/HA Composites for Bone Fixation Devices

Naoyuki Nomura, Kozue Sakamoto, Katsuya Takahashi, Seiji Kato, Yasunori Abe, Hisashi Doi, Yusuke Tsutsumi, Masahiro Kobayashi, Equo Kobayashi, Woo-Jong Kim, Kyo-Han Kim, Takao Hanawa

pp. 1449-1454

Abstract

Porous Ti (pTi)/hydroxylapatite (HA) composites were fabricated by an infiltration method in a vacuum and sintering. The Young’s modulus of the composites was evaluated before and after the immersion in Hanks’ solution. The strength of the composites was also evaluated by four-point bending test. The Young’s modulus of the compacts was governed by the porosity and was comparable to the human bone in the porosity range from 24 to 34%. The Young’s modulus of sintered pTi/HA composites was larger than that of pTi. The Young’s modulus of the sintered pTi/HA composites decreased after immersion in Hanks’ solution. The proof and bending strengths of the sintered pTi/HA composites were larger than those of pTi. Solid solution hardening of Ti by oxygen contributed the increase of the proof strength.

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Fabrication and Mechanical Properties of Porous Ti/HA Composites for Bone Fixation Devices

Production of Graphite Nanosheets by Low-Current Plasma Discharge in Liquid Ethanol

Sunghoon Kim, Ruslan Sergiienko, Etsuro Shibata, Yuichiro Hayasaka, Takashi Nakamura

pp. 1455-1459

Abstract

Graphite nanosheets were produced by low-current plasma discharge in ultrasonically cavitated liquid ethanol. The microstructure, morphology and thickness of the graphite nanosheets were characterized by scanning and transmission electron microscopy, X-ray diffraction, dynamic force microscopy and Raman spectroscopy. The results indicated that the synthesized nanosheets have many folds, curled edges and are up to 11 μm in extent. The graphite nanosheets typically ranged in thickness from 6.7 to 23.5 nm. The proposed method is substrate-free, does not require expensive vacuum equipment and nor does it consume large amounts of electricity.

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Production of Graphite Nanosheets by Low-Current Plasma Discharge in Liquid Ethanol

Effect of Feedstock Powder Characteristic on the Properties of Super-Sonic Flow Deposited Cu Coating Layer

Kee-Ahn Lee, Dong-Yong Park, Sung-Hee Kwon, Hyung-Jun Kim

pp. 1460-1466

Abstract

Copper coating was manufactured by super-sonic flow deposition method and especially two kinds of feedstock powders with different powder particle size distribution (A: 9∼53 μm, B: 4∼23 μm) and grain characteristic in the powder (A: fine and inhomogeneous, B: coarse) were used for the deposition. It was found that the use of small particle distributed feedstock powder B could decrease the surface roughness and porosity of the coating layer. After annealing, the micro-hardness of the super-sonic flow deposited copper coating decreased significantly with increasing annealing temperature. The abrupt decrease in hardness exactly corresponded to the starting annealing temperature of primary recrystallization. It was also suggested that the hardness of Cu coating layer mainly attributed to grain size, shape and the bonding of particles but not a change in the porosity of the coating layer. The electrical conductivity and thermal conductivity of powder B coating were higher than those of powder A. The superiority of electrical and thermal conductivities of B coating layer could be related not only to the large size and homogeneity of grains, and strong bonding of particle-particle interface but also to a decrease of porosity content, caused by small size and homogeneous distribution of powder B.

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Effect of Feedstock Powder Characteristic on the Properties of Super-Sonic Flow Deposited Cu Coating Layer

Effect of Heat Treatment on the Hardness of Ti-Mo-N Films Deposited by RF Reactive Magnetron Sputtering

Shoko Komiyama, Yuji Sutou, Junichi Koike

pp. 1467-1473

Abstract

The effects of heat treatment on the microstructure and hardness of Ti-Mo-N films were investigated for various N contents. Ti-Mo-N films were deposited onto a AISI304 stainless steel substrate by reactive RF magnetron sputtering in a mixture of argon (7.5 ccm) and nitrogen (0–2.0 ccm) gases using a Ti50Mo50 target. X-ray analysis of the as-deposited films indicated that the main phases of the Ti-Mo-N film produced at nitrogen gas flow rates of (fN2)≤0.2 ccm and >0.3 ccm were bcc-(Ti,Mo) and δ-(Ti,Mo)N phase, respectively. As-deposited films were heat treated in an argon atmosphere at 300–1100°C for 30 min. Hardness was measured using a nanoindentation system. There was almost no change in the hardness of the Ti-Mo-N films deposited at fN2=2.0 ccm after heat treatment. In contrast, the hardness of the films deposited at fN2=0.2 and 0.3 ccm was significantly increased by heat treatment at temperatures higher than 900°C. In particular, the film deposited at fN2=0.3 ccm showed a maximum hardness of approximately 35 GPa by heat treatment at 1000°C for 30 min. X-ray measurements and transmission electron microscopy (TEM) observations indicated that the increment of hardness in the Ti-Mo-N film deposited at fN2=0.3 ccm was due to the formation of a bcc-(Ti,Mo) phase in a δ-(Ti,Mo)N phase.

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Effect of Heat Treatment on the Hardness of Ti-Mo-N Films Deposited by RF Reactive Magnetron Sputtering

Examination of the Tensile Deformation Resistance and Ductility of Friction Stir Processed Al-Cu 2218 Alloy at Elevated Temperatures

Ssu-Ta Chen, Truan-Sheng Lui, Li-Hui Chen

pp. 1474-1480

Abstract

Tensile properties dependence of elevated testing temperatures (100°C∼450°C) on as extruded and as friction stir processed Al-Cu 2218 alloy were investigated. The tensile deformation resistance of an as friction stir processed sample is higher than an as extruded one as increased testing temperature up to 300°C and this is a consequence of natural aging effect. However, the tensile deformation resistance decreased evidently as the testing temperature raised to 400°C∼450°C, meanwhile there was a concomitant improvement of tensile ductility due to a homogeneously grain refinement which facilitated a pronounced grain boundary sliding in this temperature range.

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Examination of the Tensile Deformation Resistance and Ductility of Friction Stir Processed Al-Cu 2218 Alloy at Elevated Temperatures

Oxidative Roasting of Low Grade Zinc Sulfide Concentrate from Gagok Mine in Korea

Byung-Su Kim, Soo-Bock Jeong, Young-hun Kim, Hyung-Seok Kim

pp. 1481-1485

Abstract

A new process for utilizing low grade zinc sulfide concentrate containing a large amount of iron as a zinc and iron resource has been developed in Korea. The process largely consists of oxidative roasting and reduction-volatilization processes. In this process, zinc is recovered as zinc oxide form in the gas phase and iron is concentrated as partially reduced iron oxide compounds in the residue phase. In the present work, a kinetic study on the oxidative roasting of low grade zinc sulfide concentrate rich in iron obtained after several mineral separation processes at Gagok mine in Korea was experimentally investigated. The experiments were carried out to understand the oxidative roasting process of the zinc concentrate over a temperature range of 998 to 1073 K under air using a thermogravimetric method. The oxidative roasting rate of the zinc concentrate was found to be relatively fast under the whole temperature range and almost 95% of sulfur contained in the concentrate was removed after the oxidative roasting at 1073 K for 20 min. Sulfur removal ratio as a function of time has been analyzed by using a spherical shrinking-core model.

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Oxidative Roasting of Low Grade Zinc Sulfide Concentrate from Gagok Mine in Korea

Effect of Critical Micelle Concentration of Sodium Dodecyl Sulfate Dissolved in Calcium and Carbonate Source Solutions on Characteristics of Calcium Carbonate Crystals

Jun-Hwan Bang, Kyung Sun Song, Myung Gyu Lee, Chi Wan Jeon, Young Nam Jang

pp. 1486-1489

Abstract

Various concentrations of anionic surfactant, sodium dodecyl sulfate (SDS), were used to control the growth of calcium carbonate crystals. The obtained calcium carbonate particles were characterized by Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), laser scattering particle size analyzer and zeta potential analyzer techniques. The effect of various concentrations including critical micelle concentration (CMC) in calcium and carbonate source solutions on the polymorph, morphology, particle size distribution and zeta potential of the particles were studied. It was demonstrated that varied SDS concentrations in carbonate source solution has obvious effect on the characteristics of calcium carbonate particles, while varied SDS concentration in calcium source solution does not affect the characteristics. Also, it was observed that SDS affected orientation development of calcium carbonate crystals.

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Effect of Critical Micelle Concentration of Sodium Dodecyl Sulfate Dissolved in Calcium and Carbonate Source Solutions on Characteristics of Calcium Carbonate Crystals

Influence of Laser Plasma Soft X-Ray Irradiation on Crystallization of a-Si Film by Infrared Furnace Annealing

Naoto Matsuo, Nobuya Isoda, Akira Heya, Sho Amano, Shuji Miyamoto, Takayasu Mochizuki, Naoya Kawamoto

pp. 1490-1493

Abstract

The influence of laser plasma soft X-ray (LPX) irradiation on crystallization of a-Si film by infrared (IR) furnace annealing is investigated. The crystallization temperature by LPX irradiation followed by IR annealing is lowered down to 420°C and the grain size increases up to 270 nm. This phenomenon is related with the change in characteristics of a-Si film which is generated by the bond distortion and relaxation during the LPX irradiation. It was found that the LPX-irradiated film is constituted by the two different layers and the refractive index of upper layer was lower than that of under layer. The dangling bond density of a-Si film was also decreased by LPX irradiation to a-Si film. From these results, the crystallization mechanism is discussed.

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Influence of Laser Plasma Soft X-Ray Irradiation on Crystallization of a-Si Film by Infrared Furnace Annealing

Density, Thermal Stability and Mechanical Properties of Zr-Ti-Al-Cu-Ni Bulk Amorphous Alloys with High Al Plus Ti Concentrations

Tao Zhang, Akihisa Inoue

pp. 1494a-1494a

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Density, Thermal Stability and Mechanical Properties of Zr-Ti-Al-Cu-Ni Bulk Amorphous Alloys with High Al Plus Ti Concentrations

Mechanical Properties of Zr-Ti-Al-Ni-Cu Bulk Amorphous Sheets Prepared by Squeeze Casting

Tao Zhang, Akihisa Inoue

pp. 1494b-1494b

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Mechanical Properties of Zr-Ti-Al-Ni-Cu Bulk Amorphous Sheets Prepared by Squeeze Casting

A New Method for Producing Amorphous Alloy Wires

Tao Zhang, Akihisa Inoue

pp. 1495a-1495a

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A New Method for Producing Amorphous Alloy Wires

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