MATERIALS TRANSACTIONS
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ONLINE ISSN: 1347-5320
PRINT ISSN: 1345-9678

MATERIALS TRANSACTIONS Vol. 56 (2015), No. 5

  • Visualization of Electrochemical Reactions in All-Solid-State Li-Ion Batteries by Spatially Resolved Electron Energy-Loss Spectroscopy and Electron Holography

    pp. 617-624

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    DOI:10.2320/matertrans.M2015014

    Lithium-ion rechargeable batteries (LIBs) have become essential for business, industry, and daily life. All-solid-state LIBs with incombustible solid electrolytes are expected as next-generation batteries that are safe, long lasting, and have high energy density. The electrochemical battery reactions commonly occur around the electrode/electrolyte interfaces on a nanometer scale; thus, local-scale analysis and observation are important to improve battery performance. Transmission electron microscopy (TEM) is an appropriate technique for such local-scale analysis inside batteries. Here, we introduce two TEM techniques and explain the results of visualizing the dynamics of electrochemical reactions in all-solid-state LIBs. From the results using ex situ spatially resolved electron energy-loss spectroscopy and in situ electron holography, we reveal how Li-ions move in batteries and how they affect the crystal structures, electronic structures, and electric potential during the charge-discharge reactions.
  • Martensitic Transformation and Superelastic Properties of Ti-Nb Base Alloys

    pp. 625-634

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    DOI:10.2320/matertrans.M2014454

    Ti-Nb base alloys have been proposed as prospective candidates for Ni-free biomedical superelastic alloys due to their excellent mechanical properties with good biocompatibility, and many kinds of Ti-Nb base alloys exhibiting shape memory effect or superelasticity have been developed up to now. However, typical Ti-Nb base superelastic alloys show a small recovery strain which is less than one third of the recovery strain of practical Ti-Ni superelastic alloys. Over the last decade there have been extensive efforts to improve the properties of Ti-Nb base superelastic alloys through microstructure control and alloying. Low temperature annealing and aging are very effective to increase the critical stress for slip due to fine subgrain structure and precipitation hardening. The addition of interstitial alloying elements such as O and N raises the critical stress for slip and improves superelastic properties. In this paper, the roles of alloying elements on the martensitic transformation temperature, crystal structure, microstructure and deformation behavior in the Ti-Nb base alloys are reviewed and the alloy design strategy for biomedical superelastic alloys is proposed.
  • The Effect of Aluminum on Microstructure and Mechanical Properties of ATI 718Plus Alloy

    pp. 635-641

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    DOI:10.2320/matertrans.M2014378

    In this reported study, the influence of aluminum concentration on the microstructure and mechanical properties of alloy ATI 718Plus was investigated. The experimental results revealed that the content of aluminum has a significant effect on the solvus temperature and the chemical compositions of the γ′ and δ phases of ATI 718Plus. The experimental data showed that an increased concentration of aluminum in the alloy caused the tensile strength to increase, but had a negative impact on the metal’s ductility. The distribution of aluminum in the matrix and phases of the alloy were systematically examined using the atom probe tomography (APT) technique. The precipitation of phases in the alloy resulting from heat treatment was predicted using the JMatPro 6.0 software application and the predicted results were verified experimentally using electrolytic phase separation followed by microchemical analysis. In addition, a more detailed analysis of the size distribution of the γ′ and crystal structure of the δ phase in the alloy was performed using SEM and XRD analysis. A full discussion of the effects of aluminum content on the mechanism of the generation of the alloy microstructure and evolution of the tensile properties is included in this report.
  • The Effect on Diesel Injector Wear, and Exhaust Emissions by Using Ultralow Sulphur Diesel Blending with Biofuels

    pp. 642-647

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    DOI:10.2320/matertrans.M2014410

    To extend the engine life and to reduce exhaust pollution in diesel engines, lubrication properties were compared between the biodiesel blends and pure petroleum diesel. The biodiesel was used as lubricating additives on pure petroleum diesel at five different concentrations of 0 mass%, 10 mass%, 20 mass%, 50 mass% and 100 mass%, biodiesel blends were named B0, B10, B20, B50 and B100 biodiesel blends, respectively.
    The analysis was performed in three steps. First, the injection of biodiesel in the diesel engine channel was simulated. Second, tribological experiments were performed using ball-on-ring contact method. The wear scar diameters and wear surfaces of the tribopairs were then analyzed. The third step was comparison of biodiesel blends and pure petroleum diesel in terms of engine exhaust emitted by a turbocharged diesel engine.
    The wear experiments showed that a small addition of biodiesel to pure petroleum diesel can considerably reduce friction and wear under boundary lubrication. The third tests apply four biodiesel fuel additives on the engine performance, and exhaust emissions results are compared to the baseline (pure petroleum diesel) case. Results show that the fuel consumption is increased by 11.8% for the biodiesel case, the engine combustion temperature can be increased by 2.49% for the biodiesel case; the O2 emission can be increased by 12.85%; smoke emissions can be reduced up to 15.89%. Thus, the biodiesel additives can be applied in the diesel fuel to upgrade the engine performance.
  • Comparison of Structural Relaxation Behavior in As-Cast and Pre-Annealed Zr-Based Bulk Metallic Glasses Just below Glass Transition

    pp. 648-654

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    DOI:10.2320/matertrans.M2015023

    The α-relaxation of pre-annealed Zr55Cu30Ni5Al10 bulk metallic glasses (BMGs) was compared with that of as-cast Zr-based BMGs including Zr55Cu30Ni5Al10. The α-relaxation was investigated by volume relaxation. The relaxation behavior was well described by a stretched exponential relaxation function, Φ (t) ≈ exp [ - (tα )β α ], with the isothermal relaxation time, τα, and the Kohlrausch exponent, βα. The βα exhibited the strong temperature dependence for the pre-annealed BMG, while the weak temperature dependence was visualized for the as-cast BMG similar to the dynamic relaxation. The τα’s were modified by Moynihan and Narayanaswamy-Tool-Moynihan methods that reduce the difference in the thermal history of sample. As a result, the relaxation kinetics in the glass resembled that of a liquid deduced from the behavior of viscosity in the supercooled liquid.
  • Molecular Dynamics Analysis of the Microstructure of the CaO-P2O5-SiO2 Slag System with Varying P2O5/SiO2 Ratios

    pp. 655-660

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    DOI:10.2320/matertrans.M2014363

    The structures of the CaO-P2O5-SiO2 slag system with varying P2O5/SiO2 ratios at a fixed CaO content have been investigated by molecular dynamics simulation using the pairwise potential model. The results showed that the average bond lengths of Si-O and P-O were 1.610 ± 0.001 Å and 1.531 ± 0.005 Å in the examined range of the P2O5/SiO2 ratio. More than 95% Si and P ions were 4-coordinated and formed tetrahedral structures. Average coordination numbers of P-O and Si-O decreased slightly while average coordination number of Ca-O revealed a rising trend with the addition of P2O5. The non-bridging oxygens (Si-O-Ca and P-O-Ca) were the overwhelming majority and further increased with the substitution of SiO2 by P2O5, which results in the decrease of the polymerization constant Kp. The numbers of Si and P groups linked to a tagged Si or P tetrahedron (Qn speciation) characterized the polymerization degree of the slag system. The Q0 of both P and Si declined remarkably with the increase of P2O5. Correspondingly, (Q1 + Q2 + Q3 + Q4) of Si and P increased observably, implying that the polymerization degree of the slag system was enhanced.
  • Phase Formation and Interfacial Phenomena of the In-Situ Combustion Reaction of Al-Ti-C in TiC/Mg Composites

    pp. 661-664

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    DOI:10.2320/matertrans.M2014323

    Phase evolution and interfacial characteristics through the combustion reaction of Al-Ti-C system were investigated, in terms of the reaction mechanism. The phase formation in the reaction system at 650, 660, and 670°C by in-situ high temperature X-ray diffraction (HT-XRD) showed the formation of the solid Al3Ti phase, along with melting of the Al at 660°C. Microstructural analysis of the Al-Ti-C system after holding at 670°C was carried out to identify the reaction mechanisms, which were the formation and growth of the Al3Ti phase by dissolving Ti in molten Al. This phase occurs with further contact with C, and would initiate the combustion reaction to produce a more thermodynamically stable TiC phase. Mg-infiltrated 3.04 mm in the Al-TiC substrate was compared to 5.42 mm in the Al-Ti-C system, at the same time and temperature from the infiltration test. The apparent activation energy obtained for Al-TiC system was 350.84 kJ/mol, which was higher than that of the Al-Ti-C system (307.31 kJ/mol). The formation of the Al3Ti phase in the Al-Ti-C system was also observed from the crystal structural analysis on the infiltrated area; therefore, the in-situ combustion reaction in Al-Ti-C system promoted the wetting of Mg.
  • Effects of Molybdenum Microstructures on Sputtered Films

    pp. 665-670

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    DOI:10.2320/matertrans.M2014411

    The textures of 99.9% purity molybdenum plates in both rolled and recrystallized conditions were investigated by electron backscattering diffraction. The as-rolled molybdenum plates showed a change in texture from {001}⟨110⟩ toward {111}⟨110⟩ with increasing reduction ratio indicating that the texture can be modified through rolling schedule. Both the as-rolled and recrystallized molybdenum plates were made to sputter thin films and to examine the effects of sputtering target microstructures upon sputtered films. The as-rolled sputtering target demonstrated 11% higher sputtering rate than the recrystallized molybdenum target under the same sputtering conditions. Microstructures in the as-rolled plates bear a higher tendency to sputter due to their higher energy. The structures of the sputtering targets demonstrate pronounced effects upon the sputtered films.
  • Evaluation of Dislocation Density for 1100 Aluminum with Different Grain Size during Tensile Deformation by Using In-Situ X-ray Diffraction Technique

    pp. 671-678

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    DOI:10.2320/matertrans.L-M2015803

    Ultra-fine-grained (UFG) aluminum with a grain size of 260 nm was fabricated by annealing a severely plastically deformed A1100 alloy. The resulting UFG aluminum exhibited a 0.2% proof stress (σ0.2) that was four times larger than that predicted by the conventional Hall-Petch relation. In this study, the UFG aluminum, the fine-grained aluminum with a grain size of 960 nm and the coarse-grained aluminum with a grain size of 4.47 µm were prepared. The change in the dislocation density, ρ was investigated during tensile deformation using in-situ X-ray diffraction measurements at SPring-8. It was found that as the strain increased, the ρ changed in four distinct stages. The first stage was characterized by elastic deformation, and little change in the ρ occurred. For the coarse-grained aluminum, this stage was almost absent. In the second stage, the ρ rapidly increased until the stress reaches σII in which the plastic deformation begins to occur at a constant strain rate. In the third stage, only a moderate change in the ρ occurred. Finally, in the fourth stage, the ρ rapidly decreased as the test pieces underwent fracture. Additionally, it was found that the σ0.2I was followed by the conventional Hall-Petch relation in all grain size range.
  • Evolution of Permeability during Fracturing Processes in Rocks under Conditions of Geological Storage of CO2

    pp. 679-686

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    DOI:10.2320/matertrans.M-M2015802

    We investigated experimentally the change in permeability in three different types of soft rocks including mudstone, sandstone, and tuff from the Fureoi and Takinoue formations, which are representative of the CCS demonstration site at Tomakomai in Japan, and another type of mudstone from the Besho Fm. (B-M). Permeability during deformation, shear fracturing, and post-failure slipping is estimated from measured flow rate and differential pore pressure. In addition, the morphologies of the shear fracture zones were examined using the X-ray CT scanning technique. All the samples exhibit typical brittle-fracturing behaviors, except for the B-M sample which does not show a major shear fracture. During the fracturing process, the permeability increased by one to three orders of magnitude. Further changes in the post-failure slipping and stress relaxation regimes show strong dependence on the type of rocks. Observed changes in permeability can be interpreted as results of fracturing creation, shear zone smoothing, closure and reactivation of fractures under different stress regimes.
  • Simulation of Apparent Elastic Property in the Two-Dimensional Model of Aluminum Foam Sandwich Panels

    pp. 687-690

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    DOI:10.2320/matertrans.M2015008

    Based on its structural features, Aluminum Foam Sandwich (AFS) panels were properly simplified to two-dimensional random models through C++ and ANSYS software in this paper. The apparent elastic property of AFS panels was studied through simulation under the circumstances of different relative density, pore size range or geometric imperfections. The obtained results showed that the microstructural deformation in AFS was caused during uniaxial compression, which leaded to the increase of apparent elastic modulus with the increase of relative density. It was also found that the apparent elastic modulus of AFS panels with non-homogeneous structure was the highest and the apparent elastic modulus of AFS panels with geometric imperfections was the lowest. Moreover, the pore size range almost had no effect on the slope of the elastic stage. However, the apparent elastic modulus showed great sensitivity to the geometric imperfections. In addition, the exponential relationship between the relative densities and the relative elastic modulus was fitted. The simulation results in this work were in agreement with those found in previous theoretical and experimental results reported in other literature, which confirmed the feasibility and rationality of two-dimensional random models.
  • Effect of Alloying Elements and Generation of Hydrogen Gas on Zincate Treatment and Electroless Nickel-Phosphorus Plating of Aluminum Alloys

    pp. 691-695

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    DOI:10.2320/matertrans.M2014385

    The effect of alloying elements and the generation of hydrogen gas during zincate treatment and electroless nickel-phosphorus plating were studied by electron microscopy. Hydrogen gas was vigorously evolved during the zincate treatment for binary Al-2 at%Mg and Al-2 at%Si alloys, and the zincated surfaces were nonuniformly covered with excess coarse zinc particles due to the continuing oxidation of the substrate and reduction of proton and zincate ions. On the other hand, the surfaces of the ternary Al-2 at%Zn-0.2 at%Mg and Al-2 at%Zn-4.5 at%Mg alloys were immediately covered with a thin and uniform film of zinc.
    Magnesium in aluminum alloys and the excess precipitation of zinc were found to lower the adhesion of the electroless nickel-phosphorus plated films. When the zincated Al-2Mg and Al-2Si alloys were immersed in the plating solution, dissolution of the excess zinc generated hydrogen gas, and the plated films were poorly adhered to the substrates. Despite the thin and uniform zincate film, the plated film on the Al-2Zn-4.5Mg alloy was easily peeled off due to the voids formed between the plated film and the substrate. Magnesium in the alloy may suppress precipitation of the nickel and accelerate generation of hydrogen gas at the beginning of the plating.
  • Examination of Electrical Conduction of Carbonyl Iron Powder Compacts

    pp. 696-702

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    DOI:10.2320/matertrans.M2014311

    In this study, we report the electrical conduction of carbonyl iron powder compacts when a constant voltage/current source is supplied, especially under a typical voltage 9.7 V of electric current activated sintering (ECAS). The potential driving forces for resistance drop during stressing, including bulk temperature-dependent and -independent, were discussed. By using a proposed competition mechanism and percolation theory, it can successfully describe electrical behavior in metal powder compacts. The results indicate bulk temperature rise resulting from Joule heating is the main cause for the formation and growth of metallic contact at particle interfaces during ECAS.
  • Estimation Procedure for Volume Fraction of Minor and Rod Phase Aligned Unidirectionally in a Matrix

    pp. 703-706

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    DOI:10.2320/matertrans.M2014424

    Knowing the volume fraction of a minor phase in a composite material is important for characterizing its mechanical properties. Assuming that a rod-like phase with a constant diameter is aligned but dispersed randomly in a matrix, a mathematical model for estimating the volume fraction of a rod-like phase has been developed. This model predicts how many rods are required for an accurate estimation of volume fraction. One of the effective features of this model is that the real dimensions do not need to be considered due to the similarity of their shape. According to this model, it is sufficient to measure the area that includes at least 20 rods to estimate an accurate value for volume fraction. This prediction was confirmed by measuring a unidirectionally solidified Sn-Cu eutectic alloy system.
  • Relation between the Solidification Condition and Volume Fraction of Rod-Like Eutectic Cu6Sn5 Phase in the Eutectic Structure in Sn-Cu Alloys

    pp. 707-714

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    DOI:10.2320/matertrans.M2014427

    The Sn-Cu alloy is a typical rod-like eutectic system. The eutectic Cu6Sn5 phase is a minor phase exhibiting a rod-like structure. The volume fraction of this eutectic Cu6Sn5 (fE-Cu6Sn5) is characterized as a function of copper content and growth velocity using an image analyzer. The volume fraction variation of the eutectic Cu6Sn5 relative to copper content is classified into three regions depending on the solidified structure. In the primary β-Sn + eutectic structure and primary Cu6Sn5 + eutectic structure regions, the fE-Cu6Sn5 increased with increasing growth velocity, independent of the copper content. These were qualitatively explained by the undercooling for the growth of both phases. On the other hand, in the eutectic structure region, the fE-Cu6Sn5 increased with copper content, independent of the growth velocity. The mechanism for the volume fraction change of the eutectic Cu6Sn5 under this growth condition was discussed. In order to exhibit the eutectic structure even for the off-eutectic composition, the volume of eutectic Cu6Sn5 was primarily altered by their changed rod diameters.
  • Accurate Prediction of Welding Stress Evolution by Considering Improved Phase Transformation Model

    pp. 715-719

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    DOI:10.2320/matertrans.M2014344

    In this work, a modified Koistinen-Marburger (K-M) relationship was proposed to describe austenite-martensite transformation. The results show that the modified K-M equation was more accurate in predicting the martensite volume fraction. A cyclic uniaxial test consisted of heating and cooling was conducted to verify the accuracy of the modified model. In order to study the welding stress evolution considering the effect of martensite transformation and annealing, both the experiment and simulation on plate fusion welding were carried out. The simulation results indicated that the transformation kinetic and the recrystalization annealing both had non-ignorable effects on the stress evolution. In addition, the simulated residual stress based on the developed model compared well with the data measured by the hole drilling method.
  • Effect of Carbon Content on Heat Treatment Behavior of Multi-Alloyed White Cast Iron for Abrasive Wear Resistance

    pp. 720-725

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    DOI:10.2320/matertrans.M2015001

    Effect of carbon (C) content on heat treatment behavior of multi-alloyed white cast irons with basic alloy composition was investigated. The multi-alloyed white cast irons with varying C content of 1.73–2.34% were prepared. After annealing, the test specimens were austenitized at 1323 and 1373 K, and then hardened by fan air cooling. The hardened specimens were tempered between 673 and 873 K. It was found that the hardness in as-hardened state increased first and then decreased as C content increased. The volume fraction of retained austenite (Vγ) increased with increasing C content. In tempered state, each hardness curve showed secondary hardening due to the precipitation of secondary carbides as well as the transformation of decomposed austenite to martensite during post cooling. The Vγ began to decrease greatly when the tempering temperature was elevated over 723 K. The maximum tempered hardness (HTmax) was obtained in the specimens tempered between 798 K and 823 K where the Vγ ranged from 8 to 12%. The highest value of HTmax was obtained in the 2.00% C specimen hardened from 1373 K austenitizing and in the 2.34% C specimen hardened from 1323 K austenitizing.
  • Load Dependence of Nanoindentation Behaviour and Phase Transformation of Annealed Single-Crystal Silicon

    pp. 726-732

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    DOI:10.2320/matertrans.M2014398

    The nanoindentation behaviour and phase transformation of annealed single-crystal silicon wafers were examined. The silicon specimens were annealed at temperatures of 250, 350 and 450°C, respectively, for 15 min and were then indented to maximum loads of 30, 50 and 70 mN. The phase changes induced in the indented specimens were observed using transmission electron microscopy (TEM) and micro-Raman scattering spectroscopy (RSS). For all annealing temperatures, an elbow feature was observed in the unloading curve following indentation to a maximum load of 30 mN. Under higher loads of 50 mN and 70 mN, respectively, the elbow feature was replaced by a pop-out event. The elbow feature reveals a complete amorphous phase transformation within the indented zone, whereas the pop-out event indicates the formation of crystalline Si XII and Si III phases. The formation of these phases increased with an increasing annealing temperature and indentation load. Moreover, the hardness and Young’s modulus both decreased as the annealing temperature and indentation load increased. For the specimens annealed at 450°C and then indented to maximum loads of 50 mN and 70 mN, respectively, micro-cracks initiated at the bottom of the phase transformation region and extended into the silicon substrate. In other words, under high annealing temperatures and indentation loads, the critical load required for micro-fracture initiation was exceeded.
  • Electrochemical Leaching of Tungsten from Hard Metal Alloy Using Molten Sodium Hydroxide

    pp. 733-737

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    DOI:10.2320/matertrans.M2014316

    Hard metal alloy, which is used as material for cutting tools, comprises tungsten carbide, cobalt, and other elements and possesses excellent hardness and heat resistance. Hard metal alloy is difficult to recycle, and its rate of recycling in Japan is low. In this study, components of hard metal alloy were leached by electrolysis in molten sodium hydroxide. The optimum experimental condition was potentiostatic electrolysis at an oxidation potential of −0.7 V. Tungsten constituted 99.7 mass% of the leached component in the molten salt, and other metals oxidized to passive materials. Tantalum was dissolved in the molten salt without electrolysis. Chromium was oxidized from its metal state to its trivalent oxide, which was converted to the hexavalent oxide by trace oxygen in the atmosphere of the reactor.
  • Recovery of Platinum from Chloride Leaching Solutions of Spent Reforming Catalysts by Ion Exchange

    pp. 738-742

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    DOI:10.2320/matertrans.M2015027

    Platinum and base metals (Al, Fe, Si) are present in the chloride leaching solutions of spent reforming catalysts. In order to develop a process to recover platinum from such leaching solutions, batch and continuous ion exchange experiments were performed using a strong anionic resin (DiaionSA10AP). The adsorption equilibrium data of Pt are described by the Langmuir adsorption isotherm. Batch experiments indicate that it is possible to separate Pt and Fe from other metal ions in the present leaching solution. Fe was selectively removed from the loaded resin using diluted HCl, while Pt was eluted using thiourea after Fe removal. The results of column experiments verified the feasibility of the separation and recovery of platinum from leaching solutions using the present process. The elution efficiency exceeded 99% for both Pt and Fe. The recovery percentage of Pt from the leaching solution using this method was 99.3%.
  • Numerical Simulation of a U-Shaped ACFM Inducer

    pp. 743-748

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    DOI:10.2320/matertrans.M2015005

    A static numerical simulation model of a U-shaped ACFM inducer is built to observe the distribution of current density and magnetic field near the crack, and a dynamic model is developed from it to model a real ACFM probe passing above a real specimen with a crack. The dynamic model is verified by comparison with experimental data and shows good agreement. The influence of various parameters, such as material and dimensions of core and inducer lift-off on the perturbed magnetic field above the crack is modeled and discussed. The suggested parameters are given for the design of the inducer according to the influence analysis results. The numerical simulation results will provide guidance to the design of the U-shaped ACFM inducer.
  • Effects of Cu Addition on the Microstructure and Localized Corrosion Resistance of Hyper Duplex Stainless Steels Aged at 748 K

    pp. 749-754

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    DOI:10.2320/matertrans.M2015022

    The effects of Cu addition on the microstructure and localized corrosion of hyper duplex stainless steels aged at 748 K were investigated using TEM analysis and electrochemical test. The addition of Cu to the base alloy facilitated the precipitation of a Cr-enriched α′-phase due to an increase in the Cr activity, thereby reducing the localized corrosion resistance. The localized corrosion was initiated at the Cr-depleted regions around the Cr-enriched α′-phase.
  • Solid/Powder Clad Ti-6Al-4V Alloy with Low Young’s Modulus and High Toughness Fabricated by Electron Beam Melting

    pp. 755-758

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    DOI:10.2320/matertrans.M2015025

    A clad structure that consists of solid and powder parts was created from powdered Ti-6Al-4V utilizing electron beam melting (EBM) technique by a single process. The input energy density required to melt the raw powder material was controlled by changing the scan speed of the electron beam from 100 to 2000 mm/s. The finished products showed several types of structures: a dense solid, a periodic layered (clad) structure made up of a solid part and an unmelted powder part, and almost full powder. The products with the clad structure showed a combination of low Young’s modulus and high toughness as characterized by the presence of a stress plateau in the stress-strain curve. Both of these qualities are necessary for feasibility as implant materials used in orthopedic fields. We conclude that the products developed in this study could be useful as bone implants in terms of the mechanical similarity to bones, despite needing only an single EBM process for fabrication.
  • Effect of Heat Treatment on Ordered Structures and Mechanical Properties of Fe-6.5 mass%Si Alloy

    pp. 759-765

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    DOI:10.2320/matertrans.M2014451

    The effect of heat treatment on ordered structures and mechanical properties of Fe-6.5 mass%Si alloy is studied. It is revealed that the cooling rate has a great influence on ordering type and degree, and furthermore on ductility and micro-hardness of the alloy. Cooling in furnace leads to the development of B2 and D03 orderings, while quenching in water can suppress the formation of the D03 phase, and prevent the growth of the B2 phase. The long range order parameter (LROP) decreases with increasing the cooling rate from the disordered region, and consequently the ductility of the alloy increases and the micro-hardness decreases, which is helpful for the cold-rolling deformation. Anti-Phase Boundaries (APBs) are also examined and discussed here with concern to the long range order parameter.
  • Amenability Testing of Fine Coal Beneficiation Using Laboratory Flotation Column

    pp. 766-773

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    DOI:10.2320/matertrans.M2014462

    The amenability of beneficiating a low rank coal has been studied using a laboratory CPT CoalPro flotation column. After review of the published literature various relationships between bubble size and superficial gas rate, bubble surface area flux and gas hold up and slip velocity and bubble size have been deduced in relation to the coal slurry and compared with relationships reported in the literature. A performance curve for the flotation column tested under the operating conditions revealed that the optimal size range of coal that yields optimal separation occurred in the size range 60–200 microns. Empirical relationships a) to estimate the gas hold up in terms of the measurable quantities, such as superficial gas and water flow rates and frother concentration and b) to predict the carrying capacity of particles of various sizes into the concentrate have been developed. Based on grade/recovery plots, the optimal separation that can be achieved for the given coal in a flotation column was found to be 85% combustible recovery with 81% ash rejection at the separation efficiency of 62% along with the corresponding operating conditions. Empirical relationships to predict the recovery of combustibles and ash rejection in terms of operating variables have also been proposed.
  • A Trial on Detecting Fluctuations in Bulk Metallic Glass Beams by Strain Contrast Variation Method–Use of High Energy Small-Angle Scattering

    pp. 774-776

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    DOI:10.2320/matertrans.M2015020

    Heterogeneity in annealed Zr-Cu-Al alloys with high ductility has been examined by high-energy small-angle scattering with strain variation method. Although the statistics is still poor for detailed analysis, it was found that the heterogeneity in the sample showed clear enhancement by applied tensile strain, and the characteristic size of the heterogeneity was of the same order of magnitude as the one observed by high resolution electron microscopy. With surface insensitivity of the present method, anomalous small-angle scattering results at Cu K absorption edge for the same sample was briefly discussed.

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24 Mar. (Last 30 Days)

  1. Dependence of Carbon Concentration and Alloying Elements on the Stability of Iron Carbides ISIJ International Advance Publication
  2. Comprehensive Optimization Control Technology of Rolling Energy and Oil Consumption in Double Cold Rolling ISIJ International Advance Publication
  3. Experiments on Removal of Hydrophilic Fine Particles in Bubbly Flow ISIJ International Vol.59(2019), No.2
  4. Effects of Impurities and Processing Conditions in Al–1%Mn Alloys on the Formation of Thermally Stabilized Substructures MATERIALS TRANSACTIONS Vol.59(2018), No.11
  5. Temperature Field Distribution of a Dissected Blast Furnace ISIJ International Advance Publication
  6. Coating Film Profiles Generated by Fluctuating Location of the Wiping Pressure and Shear Stress ISIJ International Vol.59(2019), No.2
  7. Effect of EAF Slag Temperature and Composition on its Electrical Conductivity ISIJ International Vol.59(2019), No.2
  8. Fundamentals of Silico-Ferrite of Calcium and Aluminium (SFCA) Iron Ore Sinter Bonding Phase Formation: Effects of Basicity and Magnesium on Crystallisation during Cooling ISIJ International Vol.59(2019), No.2
  9. Evolution of Blast Furnace Process toward Reductant Flexibility and Carbon Dioxide Mitigation in Steel Works ISIJ International Vol.56(2016), No.10
  10. Structure Based Viscosity Model for Aluminosilicate Slag ISIJ International Advance Publication

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24 Mar. (Last 30 Days)

  1. blast furnace
  2. blast furnace permeability
  3. blast furnace productivity
  4. galvanizing
  5. tuyere abrasion
  6. tuyere erosion
  7. tuyere failure
  8. lme
  9. wear on tuyere
  10. 鉄と鋼