Kazuhiro Matsugi

Hiroshima University | HU · Graduate School of Engineering

In this paper, ternary NiFeW alloy coatings were prepared by jet electrodeposition, and the effects of lord salt concentration, jet speed, current density and temperature on the properties of the coatings, including the composition, microhardness, surface morphology, structure and corrosion resistance, were investigated. Results reveal that the dep...

The s-orbital energy level (Mk) of alloying elements in a Bi cluster was used to determine the composition for alloys of this system for use as Pb-free high-temperature solders. Binary Bi-Cu and Bi-Ag alloys with ΔMk of 0.013-0.343 and ternary Bi-2.0Ag-0.5Cu and Bi-5.0Ag-0.5Cu alloys with ΔMk of 0.180 and 0.379, respectively, were fabricated and te...

Eight ancient bimetal swords held by Hiroshima University, Japan were analyzed non-destructively through γ-ray radiography and X-ray fluorescence (XRF). ¹³⁷Cs and ⁶⁰Co γ-ray irradiation sources were used to obtain transmission images of swords. A scanning radiography method using a ⁶⁰Co γ-ray source was developed. XRF was used for qualitative eleme...

NiWP alloy coatings were prepared by electrodeposition, and the effects of ferrous chloride (\(\hbox {FeCl}_{2})\), sodium tungstate (\(\hbox {Na}_{2}\hbox {WO}_{4})\) and current density (\(D_{\mathrm{K}}\)) on the properties of the coatings were studied. The results show that upon increasing the concentration of \(\hbox {FeCl}_{2}\), initially th...

A new process, based on an infiltration and reaction method, is proposed to fabricate metal matrix composites reinforced with Al3Ni, intermetallic compounds. This study investigates the optimum conditions for refining intermetallic compound dispersion inside the metal matrix at the different reaction times (60 s, 300 s and 600 s) at molten alloy te...

In this paper, ternary NiWP alloy coatings were prepared by electrodeposition, and the effects of sodium hypophosphite (NaH2PO2) concentration on the properties of the coatings, including the deposition rate, current efficiency, composition, surface morphology, corrosion resistance, and microhardness, were investigated. Results reveal that the depo...

In this study, hybrid composites reinforced with Carbon short fibers and alumina short fibers were optimized using low-pressure casting. The total fraction of fibers in the composite was 10 vol%, with equal parts of Carbon short fibers and alumina short fibers (i.e., 5 vol% each). For comparison with the hybrid composites, two composites were separ...

A new process is proposed to manufacture carbon nanotube preform and carbon nanotube (vapor grown carbon fiber, VGCF)-reinforced aluminum matrix composite. Carbon nanotube preform is fabricated using a mixtures of mesophase pitch (MP) and VGCF. The VGCF-MP-preform-reinforced aluminum composite was manufactured by a low-pressure casting method, with...

Magnesium-calcium alloy composites reinforced with nickel-coated vapor-grown carbon fibers (VGCFs) were fabricated using a compo- casting process. Then, the microstructures and mechanical properties of these composites were investigated. The Mg-5Al-3Ca (AX53) alloy exhibited a dendritic microstructure with a coarse lamellar (Mg, Al)2Ca phase along...

The s-orbital energy levels (Mk) of some alloying elements in a Bi cluster model were obtained on the basis of the molecular orbital calculation. In contrast, binary Bi-Cu/-Ag/-Zn system alloys with ΔMk of 0.013-0.343 were manufactured and tension- or hardness-tested, where ΔMk was the compositional average of Mk. The ultimate tensile strength and...

0.5～1.0wt. % carbon nano-fiber (CNF) dispersed frame-resistant magnesium alloy was prepared by stir casting process. Starting materials were Mg-5wt%Al-3wt%Ca and VGCF as matrix and CNF. In order to disperse VGCF in alloy uniformly, Ni was coated on VGCF by electroless Ni plating before casting. As increasing VGCF contents, the microstructure of mat...

25 vol% Ni electroless-plated FeB powders were consolidated by spark sintering for the development of hard materials. The sintering curves of the FeB–25Ni powders were between those of as-received FeB without Ni addition and pure Ni powders. The maximum densification rate in the FeB–25Ni was achieved at an apparent relative density of 0.79, which w...

In order to obtain the high performance materials with high thermal conductivity, high electrical conductivity, low thermal expansion, good mechanical properties and low density, TiB2 particle dispersed aluminum (Al) composites was developed by spark plasma sintering. As these properties are affected by the dispersibility of the particles, the rela...

Pure aluminum (Al) has been used as high performance heat sink, electrical line and power supply line because of its light-weight, good thermal and electrical conductivities and high cost performance. On the other hand, the higher performance heat sink and eletrtorical line at room and high tempertture are reqired because of the increment of the po...

NiWP alloy coatings electrodeposited on pure copper substrates with additive saccharin (C7H5NO3S) contents of 0-6 g/L were investigated via scanning electron microscope (SEM), x-ray diffractometer, microhardness, polarization curves, deposition rate, and wear resistance. Results show that the corrosion resistance, microhardness, and wear resistance...

FeB-Ni hard materials were consolidated by both electroless plating and spark sintering processes for the development of ubiquitous hard materials. Uniform nickel layers were formed quantitatively on as-received FeB powder surfaces. The amorphous Ni layers transformed to poly-crystalline during spark sintering. Sintering curves of FeB-Ni compacts s...

Spark sintering behaviors of 10 vol% Fe added FeB powders with 10 μm size (here after called FeB-10Fe) were investigated in spark sintering process for the development of alternative materials of WC-Co alloys. Spark sintering behaviors of FeB-10Fe in the temperature range of 600 to 1493 K were the same in the sintering curves although their maximum...

The effect of plating temperatures between 60 and 90°C on structure and corrosion resistance for electroless NiWP coatings on AZ91D magnesium alloy substrate was investigated. Results show that temperature has a significant influence on the surface morphology and corrosion resistance of the NiWP alloy coating. An increase in temperature will lead t...

After the casting and cold drawing of fuse alloys, the joint between fuse alloys and Cu has been soldered using their parts for fabrication of AC-low voltage elements used in electric power line, which means to complex fabrication processes. As case study for the power saving, the Zn-50mass%Sn-8vol%Al2O3 and Cu was directly joined using their powde...

The effectiveness of the electronic parameter on the predicting the mechanical properties of Zn system alloys for high temperature applications was evaluated in order to satisfy both the tensile strength of 200 MPa and elongation of 5%. The electronic parameter was used s-orbital energy level (ΔMk) in this study. Promising composition of alloys wer...

A new process is proposed to fabricate an aluminum alloy matrix composite dispersed with intermetallic compound particles by using the reaction between porous nickel and molten aluminum alloy. The intermetallic compound particles reinforced aluminum alloy matrix composite was manufactured with the infiltration-reaction method. Four different specif...

By optimize the mixing conditions of powders and the conditions of the spark plasma sintering, dense 20 vol % TiB2 particle aluminum composites with uniform distribution of particles were obtained. The thermal conductivity and the mechanical properties were estimated. The experimental results were good agreement with the theoretical value based on...

This study was aimed for development of vapour-grown carbon nano-fibre(VGCNF)-reinforced aluminium matrix composites by the low-pressure infiltration process. First, VGCNF and Al powder (VGCNF + Alp) preforms for low-pressure infiltration were fabricated by spark sintering process at pressures of 5, 10, 20 and 40 MPa, respectively. Porosity of the...

The ultimate tensile strength of 250 MPa, 0.2% proof stress of 150 MPa, and fracture strain of 10% at the as-cast condition for Al-1.5Mn-X alloys, were objective in this development. As ternary elements, Ca, Mg, Ti and Zn were initially chosen and the values in Δ Mk of the s-orbital energy level in alloys were adjusted to be less than 0.017. Their...

The compositions of β type Ti alloys having shape-memory ability above 400K were proposed by alloying parameters used in the delectrons concept. They were both Ti-6Mo-2Al-1Sn and Ti-6Nb-3Mo which were designed for improvement of thermal stability in shape memory behavior of Ti-6Mo base alloy, preserving the tensile strength of 700 MPa. Their ingots...

Vapor grown carbon nano fiber (VGCF) dispersed Aluminum (Al) composites was prepared by two method; one is obtained by sintering after rolling of the mixed powders of aluminum particles and VGCF, and another is by rolling after sintering of the mixed powders. Relative density, fiber direction and the shape of aluminum particles in composites was es...

Jet electrodeposition method was used to prepare Ni-W-P amorphous alloy coating and effects of plastic deformation on the crystal structure and crystallization kinetics were investigated. Based on the results of differential scanning calorimeter, x-ray diffractometer and transmission electron microscope, it can be seen that when the plastic deforma...

The tensile properties of two types of alumina (Al2O3 and Al2O3–SiO2) and short fiber-reinforced A366 alloy composite created by low-pressure infiltration have been studied. The applied pressure and temperature of molten alloy are 0.4 MPa and 1073 K, respectively. The composite containing 10 vol.% of fiber preform was sectioned and the microstructu...

The effectiveness of the electronic parameter was evaluated in order to predict the mechanical properties of zinc system alloys for high temperature application. Firstly, the relation of ultimate tensile strength or elongation and s-orbital energy level (Δ Mk) of already reported Zn system multicomponent alloys were investigated. According to this...

A new process is proposed to fabricate an intermetallic compound reinforced aluminum alloy matrix composite by using the reaction between porous nickel and molten aluminum alloy. The intermetallic compound reinforced aluminum alloy composite was manufactured with the low-pressure infiltration process method. The amounts of the intermetallic compoun...

Although carbon nanofibers show high thermal conductivities and excellent mechanical properties, their composites do not show superior properties because the short nanofibers are discontinuous. Casting vapor-grown-carbon-fiber-reinforced pure-aluminum-matrix (VGCF/Al) composites requires a continuous VGCF preform carbon lattice and bridging between...

mass%Sn, was carried out for the control of electrical and thermal properties, for Pb-free fuse elements used in electric power line. The distribution-control of Al2O3 particles in Zn50Sn was carried out by the varying process parameters such as the temperature and period for Al2O3-addition and -stir in its melt or semi-solid. Homogeneous and heter...

In order to obtain the composites with high electrical conductivity, the vapor grown carbon fiber (VGCF) dispersed aluminum (Al) composites was fabricated by rolling and annealing from the mixture powders of VGCF and Al. The electrical conductivity of the composites along rolling direction is higher double than the composites with homogeneous struc...

A new process is proposed to fabricate an intermetallic compound, Al 3Ni particles reinforced aluminum alloy matrix composite using the reaction between nickel celmet and molten aluminum. The intermetallic compound, Al3Ni particles reinforced aluminum alloy composite was manufactured with the low-pressure infiltration process method. Nickel celmet...

20vol% titanium boride particle (TiB2) dispersed aluminum composites were prepared by spark sintering process. By controlling the mixture method, the composites with different dispersibility of the particle were obtained, and the dispersibility of particles in composites was estimated by the spatial distribution of particle number in local area qua...

Spark sintering behaviors on mixed powders of Fe-B and Fe with low cost were investigated to develop the hard materials as substitution of WC-Co alloys. The cheap powders with mean composition of Fe-19.1 wt%B consisting of mixed phases of B, FeB, Fe2B and Fe were ball-milled for crushing the particles with 45/μm. The ball milled Fe-B powders with 1...

UD-SiC/SiC composite is SiC matrix reinforced with near-stoichiometric silicon carbide (SiC) fiber reinforcements, pyrolytic carbon (PyC) layer interphases. The composite was fabricated by nano infiltration and transient eutectic phase (NITE) process, and the specimens were irradiated under a flux of 7.0 × 1025 n/m2 that corresponded for the SiC co...

A new process is proposed to fabricate an intermetallic compound-reinforced aluminum alloy matrix composite using the reaction between porous nickel and molten aluminum alloy. The intermetallic compound-reinforced aluminum alloy composite was manufactured with the infiltration process method. Porous nickel reacted with the molten aluminum alloy at...

A new process is proposed to fabricate an intermetallic compound reinforced aluminum alloy matrix composite using the reaction between porous nickel and molten aluminum. The intermetallic compound reinforced aluminum alloy composite was manufactured with the infiltration process method. Porous nickel reacted with molten aluminum at 1023 K, and the...

Al 3 Ni particles reinforced Aluminum alloy composites are fabricated by low pressure infiltration method. To generate Al 3 Ni particles, Nickel porous with 3 different specific surface area were used, 1250 m 2 /m 3 , 2800 m 2 /m 3 , 5800 m 2 /m 3. Porous nickel reacted with the molten aluminum alloy at 973 k and holding time of 600 s, the applied...

Neck-seeds among pure titanium powders were homogeneously caused by the pulse discharge as an early stage in spark sintering. Their compacts showed some characteristic microstructures by the adjustment of process parameters such as temperature-history, -amplitude and applied pressure in the following continuous current discharge. Such property-cont...

The addition of 8 vol%Al2O3 particles in the Sn-50Zn was carried out for the control of electrical and thermal properties, for Pb-free fuse elements used in electric power line. The metal matrix composite of the SnZn alloy and Al2O3 particle having the different densities and melting points could be produced by the handling at coexisting range of b...

20vol% titanium boride particle (TiB2) dispersed aluminum composites were prepared by spark sintering process. By controlling the mixture method, the composites with different dispersibility of the particle were obtained, and the dispersibility of particles in composites was estimated by the spatial distribution of particle number in local area qua...

A new process is proposed to fabricate an intermetallic compound, Al3Ni particles reinforced aluminum alloy matrix composite using the reaction between nickel celmet and molten aluminum. The intermetallic compound, Al3Ni particles reinforced aluminum alloy composite was manufactured with the low-pressure infiltration process method. Nickel celmet r...

The objective of this work is to develop a manufacturing method for porous SiO 2. Porous SiO 2 was fabricated by decarburization after sintered at 1472K with carbon particles. Porosity of C20SiO 2 (added carbon particles of 20 vol%), C40SiO 2 (added carbon particles of 40 vol%), C60SiO 2 (added carbon particles of 60 vol%) and C80SiO 2 (added carbo...

抄録 A lot of powders having a low sinterability show the attractive properties for the industrial applications in the point of the energy conservation. The relation between their powders and process parameters in spark sintering was reported for production of sintered compacts with high efficiency and multifunction. The non-equilibrium phase (supers...

The compositions of β type Ti alloys having shape-memory ability above 373K and tensile strength of 600MPa, were optimized by both parameters proposed in the d-electrons concept. Promising alloys were Ti-6Mo, Ti-6Mo-3Al, Ti-6Mo-3Cu and Ti-6Mo-2Al-1Cu in mole%. Their ingots with high purity and without contamination from the crucible used, were prod...

抄録 Unprecedented phenomena were discovered by tempering the Ti-4Fe-7Al alloy quenched from the β (bcc) field. The alloy became very hard when it was tempered at 450℃ for several minutes, and severely rugged surface was generated. The inverse shape recovery phenomenon was also discovered when a quenched specimen that had been bent at room temperatur...

抄録 The influence of Al content on the evolution of microstructures and mechanical properties of Ti-xFe-yAl alloys quenched from a β field was investigated via hardness measurements, tensile tests, scanning electron microscopy (SEM) equipped with electron back scattering pattern (EBSP) analyzer, and conventional transmission electron microscopy (TEM...

The sintering behaviors and process parameters of some compounds (carbides, oxides, sulfides, borides) were investigated experimentally. These compounds were successfully consolidated and showed high densities. Some unique phenomena such as retardation of grain growth, suppression of thermal decomposition and maintenance of initial non-equilibrium...

SiC/SiC composite is a candidate material for demonstration fusion power reactor (DEMO). To identify the inherent anisotropy of composites, it requires predicting axial/off-axial mechanical properties by various failure modes. This study evaluated failure behavior of SiC/ SiC composites by various mode tests such as tensile, Inter-laminar shear and...

The unidirectional coal-tar pitch based carbon fiber (CF) reinforced Aluminum (Al) composites were fabricated by using low pressure infiltration process. In order to degrade the infiltration pressure and reactivity between CF and Al, copper (Cu) particle was introduced in CF preform by spark sintering. Dense composites were obtained by controlling...

The martensitic transformation temperature in addition to the tensile strength and oxidation resistance, were able to be estimated in the crystal structure map using both parameters of the bond order and d-orbital energy level of elements, for the design of TiNi shape memory compounds. The ternary TiNi-(Cr, Re, Fe, Cu, Al) intermetallics having the...

The unidirectional carbon fiber (CF) reinforced aluminum (Al) composites have been fabricated by the low pressure infiltration (LPI) of molten Al into porous CF preform. Prior to the fabrication of the unidirectional CF/Al composites, the unidirectional CF preform was prepared by sintering of CFs and copper (Cu) particles under the spark plasma sin...

The spark sintering technique was utilized to fabricate ubiquitously hard-materials compacts which were 0, 10 and 50vol% Fe added (hereafter called, 100, 90 and 50%FeB, respectively) in as-received powders with mean composition of Fe-19.1 wt%B. Rockwell hardness number on C scale was changed 63 to 70 depending on Fe contents, and the value of 100%F...

The unidirectional carbon fiber (CF) preform for carbon fiber reinforced aluminium (CF/Al) composites has been investigated in terms of the fabrication condition and the strength property. The CF preform which consists of CFs and Cu particles was fabricated by spark plasma sintering (SPS) process with different fabrication temperatures. In order to...

In order to evaluate the stability in long time for the performance of AC-low voltage fuses, this study aimed to measure the changes of the specific resistivity, specific heat and thermal conductivity due to the microstructure-change, using a diffusion couple consisting of the Sn-9Zn fuse element and Cu-connector which are exposed at 443 K for 7.2...

Optimization in both alloy-composition and manufacture-process has been required to obtain the TiNi-X compounds with high-strength and -oxidation resistance. Both Ti-49 mol%Ni-1 mol%Cr and Ti-45Ni-5Cr were designed for the achievement of tensile strength of 500 MPa and 800 MPa, respectively, and high oxidation resistance, by the d-electrons concept...

In this study, the fabrication of carbon containing aluminum composites was attempted by using low-pressure infiltration method. At first, porous preform containing vapor grown nano-fiber (VGCF) and pure aluminum powder was fabricated by spark plasma sintering (SPS) method. Porosity in preform was controlled by changing the applied pressure during...

The α+β type Ti-5.5Al-2Fe and β type Ti-2.5Fe-2Mn-2Zr alloys have been theoretically designed, for the modification of Ti-6A1-4V and the achievement of the high tensile strength more than 1000 MPa at the solution treatment state, respectively, using ubiquitous alloying elements in order to establish the strategic method for suppressing utilization...

Vapor-grown carbon fiber (VGCF) reinforced aluminum matrix composites were fabricated by plasma sintering method, and their mechanical and thermal properties were investigated. The aluminum powders with average diameters of 1 mu m, 3 mu m and 30 mu m were chosen as the matrix. The monolithic aluminum blocks were also fabricated by plasma sintering...

Low-pressure infiltration technique is useful for the preparation of high performance composites with large size and complex shape. In this study, the porous preform was fabricated from Al_2O_3 short fiber with 3μm in diameter. AC8A molten aluminum alloy was attempted to infiltrate perform of the various volume fractions. Al_2O_3 fiber preform with...

Copper (Cu) film was deposited on ion conductor glass, and then the electrical potential was applied to Cu coated glass at several hundred temperatures. Then, the time dependence on current density and microstructure was investigated. Consequently, the mobility of positive ion was obeying the thermal activation process. When the coating metal chang...

10 vol % vapor grown carbon fiber (VGCF) dispersed pure aluminum matrix composites was fabricated by spark plasma sintering (SPS) method. Then, by using some aluminum powders with different diameter (1-30μm) as starting material, the effect of microstructure on thermal and electrical conductivities was investigated. As increasing a diameter of alum...

Vapor grown carbon fiber (VGCF) reinforced aluminum matrix composites were fabricated by spark sintering processes. VGCFs in composites became to be dispersed uniformly in the aluminum matrix by decreasing a diameter of aluminum powder. The electrical conductivity of composites was reduced remarkably compared with monolithic aluminum block. On the...

Vapor grown carbon fiber reinforced pure aluminum matrix composites were fabricated by the hot-pressing method below the melting temperature of pure aluminum. The surface structures of the vapor grown carbon fibers and the interfacial structures between the fibers and the matrix in the composite were observed. The precipitation mechanism of crystal...

The densification or sintering processes in spark sintering has systematically investigated from the standpoint of punch-powder compact-die system, unlike the conventional situation such as the simple convenient method for fabricating sintered body. The systematic investigation consists of the following serial subjects; (1) clarification of princip...

The spark sintering technique was utilized to fabricate WC-16mass%(Ni-P) compacts with different P contents using two starting powders, Ni plated WC particles by elctroless Ni plating solutions with different P contents and their elementally blended ones. The sintering temperature decreased as P content in Ni binders increased, and all compacts had...

Ti-5.5Al-2Fe alloy has been theoretically designed by modification of Ti-6Al-4V alloy, using ubiquitously alloying elements in order to establish the strategic method for suppressing utilization of rare metals. The utilization of the cold crucible levitation melting (CCLM) is very useful, because titanium is very chemically reactive at high tempera...