Showing papers in "International Journal of Refractory Metals & Hard Materials in 1997"
TL;DR: In this article, the electromechanical behavior of WC-Co is modelled using the behaviour of pure WC and Co(W,C) alloys, according to a linear rule of mixtures.
Abstract: In long-life applications, the corrosion properties of cemented carbides can have a large influence on overall performance. Cemented carbides with improved corrosion resistance have been developed and are now commercially available. The understanding of the corrosion behaviour has been mostly empirical and satisfying explanations of the relationship between the electromechanical behaviour and in-service corrosion have been lacking. In this paper, the electromechanical behaviour of WC-Co is modelled using the behaviour of pure WC and Co(W,C) alloys, according to a linear rule of mixtures. By comparing WC-Co with WC-Ni(Cr,Mo) in both normal sulphuric acid and a synthetic mine water, it is shown that the behaviour of the two grades is inherently different. WC-Co exhibits a ‘pseudo-passivity’ during electro-mechanical tests but corrodes actively in industrial applications. In contrast, WC-Ni( Cr,Mo) passivates and the rate of corrosion can be several orders of magnitude lower than that of WC-Co.
163 citations
TL;DR: In this article, the ability for a transition metal to react with carbon increases with its number of electron vacancies in d -orbitals, and the most powerful elemental catalysts are Co, Fe, Mn, Ni and Cr. This model predicts that the most commonly used catalyst components for the commercial production of synthetic diamond under high pressure.
Abstract: The ability for a transition metal to react with carbon increases with its number of electron vacancies in d -orbitals. Elements (e.g. Cu, Zn) with no d vacancies are inert relative to carbon. Elements (e.g. Fe, Co) with few d -vacancies are effective carbon solvents. Elements (e.g. Ti, V) with many d -vacancies are carbide formers. Transition metals with intermediate reactivities can attract carbon atoms in graphite without forming a carbide. Such a moderation of interaction may catalyze the graphite → diamond transition in the diamond stability field and its back conversion in graphite stability field. The catalytic conversion of graphite to diamond, under high pressure in a molten metal, proceeds by nucleation and growth. Graphite will first be disintegrated into flakes by the invasion of liquid metal. These flakes are then puckered by the catalytic action of liquid metal that pulls every other carbon atom away from the basal planes of graphite. The puckering converts a graphite flake into a diamond nucleus that grows by feeding on either carbon atoms dissolved, or graphite flakes suspended in the molten catalyst. The capability of a catalyst to nucleate and grow diamonds under high pressure may be modeled by its atomic size and electronic configuration. This model predicts that the most powerful elemental catalysts are Co, Fe, Mn, Ni and Cr. These transition metals are the most commonly used catalyst components for the commercial production of synthetic diamond under high pressure. The catalytic power, as already determined is based on a microscopic mechanism described in this research, also correlates well with the activation energies calculated from macroscopic kinetics data available in literature
152 citations
TL;DR: In this paper, the progress in monolithic Si3N4 and SiC as well as in Si 3N4/SiC-composites for structural applications is reviewed.
Abstract: The progress in monolithic Si3N4 and SiC as well as in Si3N4/SiC-composites for structural applications is reviewed. The conventional processing including the powder synthesis, densification and microstructural design is discussed. The mechanical properties of the resulting silicon based non-oxide ceramics and their industrial applications as structural components are summarized. As an alternative route to fabricate Si3N4/SiC composites the hybrid processing utilizing the thermal conversion or organosilicon precursors to amorphous and polycrystalline multicomponent materials is described. The hybrid processed ceramics exhibit ultra-high temperature stability with respect to crystallization, oxidation and decomposition.
130 citations
TL;DR: In this paper, the results of a comprehensive investigation into the abrasion resistance of WC-Co alloys, as measured by the ASTM Standard B 611-85 test, were reported.
Abstract: This paper reports the results of a comprehensive investigation into the abrasion resistance of WC-Co alloys, as measured by the ASTM Standard B 611-85 test. The alloys ranged from 3 to 50 wt% and from 0.6 to 5 μm average grain size. Careful control of the grain size has led to new results and new insight into the relationships between abrasion resistance, hardness, cobalt content, grain size and mean free path.
100 citations
TL;DR: In this article, the authors compared the properties of Ni-Fe-Co-WC-based cemented carbides with results published in the literature, and showed how calculations can be used to select suitable compositions of these complex alloys.
Abstract: The alternative binder metals to cobalt in cemented carbides, iron and nickel, are today utilised to a minor extent only. This is largely due to the excellent properties offered by cobalt and in particular when it is used in combination with tungsten carbide, WC. However, the difficulties involved when selecting the composition of the binder metal and in particular of the carbon content of the alloy, when other metals than cobalt are involved, might have influenced the development process. The knowledge of the constitution of the systems of importance for cemented carbides, based upon these elements, has increased during the past 10–15 years. New computational tools for the description of higher-order systems have also increased the possibilities of overcoming many of the problems encountered when using iron and nickel as binder metals in cemented carbides. The present work shows how calculations can be used in the process of selecting suitable compositions of these complex alloys. The calculations are compared with new experimental results on Ni-Fe-Co-WC-based cemented carbides as well as with results published in the literature.
80 citations
TL;DR: In this paper, a series of cemented tungsten-carbides with different binder phases consisting of combinations of cobalt, nickel and chromium have been subjected to erosion-corrosion testing using a silica-water slurry.
Abstract: A series of cemented tungsten-carbides with different binder phases consisting of combinations of cobalt, nickel and chromium have been subjected to erosion-corrosion testing using a silica-water slurry. The polarisation characteristics of these cermets have been investigated using a potentiodynamic technique. The differences in binder composition influences the cermets' properties and corrosion behaviour, which in turn affects the synergistic action of erosion-corrosion. The inherent corrosion resistance of a pure nickel binder did not increase the slurry erosion resistance of the cermets, but the nickel-chromium-cobalt grades were found to improve the erosion-corrosion behaviour compared to the pure cobalt binder grade. Comparisons are made between the properties and behaviour of Ni-Cr-Co based cermets and pure metal grades with compositions similar to those found in the binder phase of the corresponding cermet grades. Explanations are advanced to explain the differences in behaviour linked to composition and mechanical properties.
79 citations
TL;DR: The development of low pressure deposition of continuous, high quality, diamond film was a major breakthrough in materials science that has allowed an economical use of diamond as an engineering material.
Abstract: The development of low pressure deposition of continuous, high quality, diamond film was a major breakthrough in materials science that has allowed an economical use of diamond as an engineering material. It has also precipitated similar research in other superhard materials, such as cBN, C3N4 and superlattice nanolayer structures. This paper will highlight basic and applied aspects of diamond coatings, and present a technology perspective on the preparation of diamond-coated tools. Some of the key factors affecting the adhesion of diamond to cemented carbide will be discussed. The performance characteristics of the diamond tools and the anticipated applications will be reviewed.
71 citations
TL;DR: In this article, the structure of a nonstoichiometric titanium carbide in disordered state and as-annealed condition was studied and it was assumed that microhardness increases owing to the grain being comminuted as a result of the formation of ordered phases.
Abstract: A study is made of the structure of a nonstoichiometric titanium carbide TiC y in the disordered state and in the as-annealed condition. Annealing carbides with different carbon content is found to give rise to various types of ordered phases. On annealing, a nonstoichiometric titanium carbide exhibits an increase in microhardness. It is assumed that microhardness increases owing to the grain being comminuted as a result of the formation of ordered phases.
52 citations
TL;DR: In this paper, hardness measurements on WC-6 wt%Co of three different grain sizes in the temperature range from −196 to 900 °C were reported and it was confirmed that hardness decreases with increasing grain size over the whole range of temperatures and it has been shown that the decrease in hardness with increasinggrain size follows a Hall-Petch-type relationship at all the temperatures tested.
Abstract: This paper reports hardness measurements on WC-6 wt%Co of three different grain sizes in the temperature range from −196 to 900 °C. Coarser grades have been found to soften with increasing temperature at a higher rate than finer grades. It has been confirmed that hardness decreases with increasing grain size over the whole range of temperatures and it has been shown that the decrease in hardness with increasing grain size follows a Hall-Petch-type relationship at all the temperatures tested.
51 citations
TL;DR: In this paper, conditions have been established for milling and sintering to yield flaw-free products with porosity rating of 1.5 for critical parameters, such as, grain size, carbon balance, impurities and composition.
Abstract: Industrial scale production of nanostructured WC-Co powders (NANOCARB® Powder) with WC grains of 1.5 for critical parameters, such as, grain size, carbon balance, impurities and composition. Conditions have been established for milling and sintering to yield flaw-free products with porosity rating of
50 citations
TL;DR: In this paper, the authors reviewed some new developments in hard materials during the last decade: new approaches to diamond synthesis including chemical vapor deposition and the laser QQC method, tetrahedral carbons, deposition of cubic boron nitride, ternary boronal carbon-nitrogen and borón-carbon-silicon phases.
Abstract: This paper reviews some new developments in hard materials during the last decade: new approaches to diamond synthesis including chemical vapor deposition and the laser QQC method, tetrahedral carbons, deposition of cubic boron nitride, ternary boron-carbon-nitrogen and boron-carbon-silicon phases. The issue of ultimate hardness of diamond reappeared again because of pseudopotential calculation of cohesive energy of a hypothetical β-C 3 N 4 structure. The stability of carbon nitride phases is analyzed in connection with the authors study of synthesis and structure of carbon nitride by nitrogen microwave plasma. Only soft graphitic CN x , x phase, stable up to 900 °C, survived criticism.
TL;DR: In this paper, the mass-loss technique was used to study the corrosion resistance of niobium, tantalum and Nb-20, 40, 60 and 80 wt% Ta alloys in boiling 20, 40 and 60 wt%.
Abstract: The corrosion resistance of niobium, tantalum and Nb-20, 40, 60 and 80 wt% Ta alloys in boiling 20, 40, 60 and 80 wt% H 2 SO 4 solutions is studied using the mass-loss technique. The corrosion rates of all materials increase with acid concentration and diminish initially with time. After nearly 200 h, the corrosion rates stabilize due to superficial oxide formation. The corrosion resistance increases with tantalum content. A preferential dissolution of niobium from the Nb-Ta alloys is noted. Recrystallization heat treatments reduce slightly the corrosion rates. The anodized materials are more corrosion resistant than the untreated ones during the first 200 h, but behave similarly for longer exposure times.
TL;DR: The successful synthesis of diamond by chemical vapor deposition (CVD) at low pressures has generated renewed interest in polycrystalline diamond as discussed by the authors, which is nearly equivalent in optical, thermal and mechanical properties to single crystal diamond.
Abstract: The successful synthesis of diamond by chemical vapor deposition (CVD) at low pressures has generated renewed interest in polycrystalline diamond. It is now possible to deposit on relatively large surfaces a metal-free ‘polycrystalline diamond ceramic’, which is nearly equivalent in optical, thermal and mechanical properties to single crystal diamond. Some microstructures found in CVD diamond are clearly related to those seen in natural ballas and the possibility of making an even better ‘polycrystalline CVD diamond’ and exploiting its capabilities is considered here.
TL;DR: In this paper, the existence of fatigue phenomena and their life time limiting influence on components of these materials under cyclic loads at room temperature were proved from experiments in a simple apparatus under three different loading conditions, static, monotonically increasing and cyclic load conditions.
Abstract: Hard metals and cermets are submitted as cutting materials to complex loadings, wear, mechanical and thermomechanical loadings. Among these the cyclic load conditions occur always with different amplitudes in the technical cutting processes. In contrast to this fact, the cyclic loading and a possible fatigue as a life time limiting process of the cutting tools received relatively little attention in the past. Our investigations since 1992 have proved the existence of fatigue phenomena and their life time limiting influence on components of these materials under cyclic loads at room temperature. These results are obtained from experiments in a simple apparatus under three different loading conditions, static, monotonically increasing and cyclic loads. Beside this quantitative phenomenological description of the fatigue by the measured mechanical properties, investigations of the microstructure of fractured surfaces by SEM and of the volume, especially around the crack tips by TEM, have led to the conclusion that the fatigue processes are located predominantly in the ductile binder phase of these composite materials. This result led to new information about the processes in the microstructure during fatigue. The investigations in this work here were carried out with different hard metals and cermets. They differ in the compositions of the brittle ceramic and of the ductile binder phase. The new results from these two routes of investigations, mechanical properties and microstructure, allow important conclusions to be drawn about the processes and the mechanisms which are responsible for the damage in the materials during fatigue. This knowledge allows the design of improved materials with regard to higher resistance against fatigue under cyclic alternating loads.
TL;DR: In this article, the effect of various impurities and micro-alloying additions (B, N, C, O, Al, Si, S and P) on the intrinsic resistance of the ∑3 (111) grain boundary in tungsten has been investigated using the molecular dynamics simulation.
Abstract: The effect of various impurities and micro-alloying additions (B, N, C, O, Al, Si, S and P) on the intrinsic resistance of the ∑3 (111) grain boundary in tungsten has been investigated using the molecular dynamics simulation. The atomic interactions have been accounted for through the use of Finnis-Sinclair interatomic potentials. The fracture resistance of the grain boundary has been characterized by computing, in each case, the ideal work of grain boundary separation, the mode I stress intensity factor and the Eshelby's F1 conservation integral at the onset of crack propagation. The results obtained suggest that pure tungsten is relatively resistant to grain boundary decohesion and that this resistance is further enhanced by the presence of B, C and N. Elements such as O, Al and Si however, have a relatively minor effect on the cohesion strength of the ∑3 (111) grain boundary. In sharp contrast, S and P greatly reduce this strength making tungsten quite brittle. These findings have been correlated with the effect of the impurity atoms on material evolution at the crack tip.
TL;DR: In this paper, phase relations, microstructure, and hardness and fracture strength of powder metallurgically processed 90 mass% [(1 − y )WC− y VC]−10 mass% Co alloys are studied.
Abstract: As an effort to investigate a possible extent of substitution of W, the metal from strategic mineral, by a less strategic V, phase relations, microstructure, and hardness and fracture strength, of powder metallurgically processed 90 mass% [(1 − y )WC− y VC]−10 mass% Co alloys are studied. Throughout the composition eight phases, α-Co, β-Co, WC, V 4 C 3 , V 8 C 7 , η 3 (Co 3 W 3 C ), η 6 (Co 6 W 6 C) and graphite C(g), were encountered and a distinct microstructural difference existed across midcomposition. On the basis of combined mechanical properties of hardness and fracture strength the alloys between y = 0.2 and 0.4, which correspond to 18–36 mass % VC, were most promising. Contrary to the antagonistic relations between hardness and toughness commonly encountered in cemented carbides and hard materials, the hardness and fracture strength of the present WC-VC-10Co alloys were nearly parallel.
TL;DR: In this article, the influence of the structure of hardmetals of two classes, tungsten carbide-base cobalt bonded and titanium carbide base steel bonded, in two different wear conditions, erosive and adhesive wear, has been investigated.
Abstract: The influence of the structure of hardmetals of two classes, tungsten carbide-base cobalt bonded and titanium carbide-base steel bonded, in two different wear conditions, erosive and adhesive wear, has been investigated. It has been shown that the wear resistance is much more structure sensitive than any single mechanical property. The structure sensitivity of adhesive wear is much higher than that of erosive and this is related to differences in stress-strain states and fracture mechanics during wear. At equal levels of hardness and approximately equal levels of strength, the adhesive wear resistance of TiC-base steel bonded hardmetals (on the contrary to their resistance to erosion) is as good as that of conventional WC-base cobalt bonded hardmetals.
TL;DR: In this article, the properties of two Mo-based alloys with different bulk compositions, recrystallized by either furnace annealing or rapid heating followed by quenching, are studied as a function of heating temperature by mechanical test, scanning electron microscopy, Auger electron spectroscopy and computer simulation.
Abstract: Characteristics of strength and plasticity, fracture mode and grain boundary segregation for two Mo-based alloys with different bulk compositions, recrystallized by either furnace annealing or rapid heating followed by quenching, are studied as a function of heating temperature by mechanical test, scanning electron microscopy, Auger electron spectroscopy and computer simulation. There exists an essential difference in both segregation behaviour and mechanical properties between as-annealed and as-quenched structural states. The rapid quenching causes strong oversaturation of the grain boundaries. In this case, intergranular enrichment is approximately twice as high as that in as-annealed alloys, and spontaneous nucleation of brittle microcracks is observed at certain embrittled boundaries. The proposed high-speed heat treatments are considered as a promising method for modelling of the structural states of the heat-affected zone of weldments. The results obtained are discussed from the viewpoint of possible reasons of impurity-induced embrittlement of Mo-based alloys.
TL;DR: In this article, the properties of binder alloys and mixtures that relate to possible composition of the binder phase in cemented carbide alloys with some emphasis on the sub-stoichiometric state in metal carbides were examined.
Abstract: This paper examines the properties of binder alloys and mixtures that relate to possible composition of the binder phase in cemented carbide alloys with some emphasis on the sub-stoichiometric state in metal carbides. The investigation looks for a better understanding of the role of carbon deficiency in the performance of alloys in industrial applications. Cobalt was the primary metal chosen for the study with a small companion study of nickel. Low concentrations of carbon; tungsten; a simple mixture of tungsten and carbon; tungsten carbides of both high and low carbon content; di-tungsten carbide; and a solid solution of 50/50 tungsten-titanium carbide were pressed, sintered and heat treated. Sintered materials were tested for mechanical properties in tension and for magnetic properties in strained and unstrained conditions. With the exception of carbon all the alloy additions exhibited some degree of solution strengthening. Tungstentitanium carbide was found to be the most effective additive followed closely by di-tungsten carbide and metallic tungsten. Some relationship was found between mechanical and magnetic properties. Results support a model where WC acts as the primary solution strengthening agent. Tungsten in solution caused by the presence of sub-stoichiometric tungsten carbide further increases the solution strengthening.
TL;DR: In this paper, temperature dependence of fracture toughness of molybdenum sheet was studied in the temperature range of 196-300 °C and it was found that nonmonotonous behaviour of this dependence is due to the change in cleavage crack nucleation mechanism.
Abstract: Temperature dependence of fracture toughness of molybdenum sheet was studied in the temperature range — 196–300 °C. It was found that nonmonotonous behaviour of this dependence is due to the change in cleavage crack nucleation mechanism.
TL;DR: In this article, a model for the domain formation in CVD K-Al 2 O 3 was presented, where columnar, twinned K-grains with an aspect ratio of about 5 and equiaxed grains, respectively, were observed to grow epitaxially on two twin-related K-domains.
Abstract: Multilayer coatings of TiN and K-Al 2 O 3 have been examined by x-ray diffractometry, scanning electron microscopy and analytical transmission electron microscopy. Thc general microstructure of the coatings, such as grain size, grain shape, twinning, dislocations, pores and interfaces was investigated and, based on these findings, conclusions about the detailed structure of K-Al 2 O 3 were made. A model is presented for the domain formation in CVD κ-Al 2 O a . The height of the columnar, twinned K-grains was of the order of the K-layer thickness. The preferred growth direction for κ-Al 2 O 3 was along the c-axis. The grain morphology is very different for TiN deposited on to cemented carbide as compared to TiN deposited on to κ-Al 2 O 3 ; columnar grains with an aspect ratio of about 5 and equiaxed grains, respectively. No pores or dislocations could be found within the TiN and κ-Al 2 O3 layers. However, κ-Al 2 O 3 /TiN interfaces below the TiN-layers exhibit a large number of pores. The deposition rate of TiN was two-thrce timcs higher for TiN deposited on cemented carbide than for TiN deposited on to κ-Al 2 O 3 . Epitaxy was frequently found both for TiN on κ-Al 2 O 3 and for κ-Al 2 O 3 on TiN. Three twin-related K-domains grew epitaxially on two twin-related TiN domains which grew epitaxially on three twin-related κ-domains. The orientation relationships could be described as: (001) κ // (111)TiN // (001) κ [100] κ1 [112] TIN1 [100] κ1 [110] κ2 // [112] TIN2 // [110] κ2 [110] κ3 [110] κ3 The observed twinning of TiN on κ-Al 2 O 3 indicates that the (001)-planes in K-Al 2 O 3 are close-packed in an..ABAC.. stacking sequence. There are two types of geometrical relationships of neighbouring domains in CVD K-Al 2 O 3 : (i) twin-related domains due to different positions of the aluminium ions within the oxygen-ion sub lattice and; (ii) translation-related domains due to differcnt stacking sequences of the oxygen-ion planes.
TL;DR: In this paper, the coatings of titanium composites containing in situ synthesized carbides or nitrides were deposited by reactive plasma spraying, which showed high sliding wear resistance and good corrosion performance.
Abstract: In this investigation, coatings of titanium composites containing in situ synthesized carbides or nitrides were deposited by reactive plasma spraying. Titanium powders were used as starting powder materials. Methane and nitrogen were used as reactive gases. Microstructural analyses revealed that titanium carbides and nitrides were synthesized during spraying. The coatings show high sliding wear resistance and good corrosion performance.
TL;DR: In this paper, a three-dimensional lattice model for the study of the recrystallization and grain growth of tungsten wires in comparison to additional experiments is presented.
Abstract: This paper describes a three-dimensional lattice model for the study of the recrystallization and grain growth of tungsten wires in comparison to additional experiments. Microstructures similar to experimental ones were obtained. The experimentally obtained grain size data was used to determine the grain growth exponent and the activation energy for grain boundary migration at temperatures ranging from 1500 to 1900 °C. The evolution with time and temperature of the average grain size has been calculated by the Monte-Carlo method. For this, a relation between length and time scale in simulation and experiment, based on intrinsic material parameters, was developed. In general, the results agree very well with the experimental observations.
TL;DR: In this article, the dispersion relation of surface acoustic waves in TiN hard films of various thicknesses on high speed steel (HSS) is studied using Brillouin scattering, and the results are interpreted on the basis of a model for supported layer modes which is based on the elastic properties of the two media and the boundary conditions at the interface and free surface.
Abstract: The dispersion relation of surface acoustic waves (SAW) in TiN hard films of various thicknesses on high speed steel (HSS) is studied using Brillouin scattering. The results are interpreted on the basis of a model for supported layer modes which is based on the elastic properties of the two media and the boundary conditions at the interface and free surface. Good agreement is obtained between theory and experiment for thick layers (≥ 0.89 μm) and for the substrate alone. High temperature measurements on a 4.18 μm coated sample up to 600 °C are reported.
TL;DR: In this article, the aim was to produce V 8 C 7 -WC and V 4 C 3 -WC powders with grain size between 1 and 2 μm, as a first stage of the preparation of fine grained WC-VC-Co hardmetal.
Abstract: The aim of this work was to produce V 8 C 7 -WC and V 4 C 3 -WC powders with grain size between 1 and 2 μm, as a first stage of the preparation of fine grained WC-VC-Co hardmetal. V 8 C 7 -WC powder was produced via two routes: starting from preformed V 8 C 7 and WC, and starting from V 2 O 5 , WC and carbon black. The V 4 C 3 -WC powder was not produced because all attempts led to the formation of W 2 C or V 8 C 7 .
TL;DR: In this article, the authors describe a cemented carbide material with an iron-based binder, which is expected to bridge the gap between high speed steels and conventional carbides.
Abstract: This paper describes a cemented carbide material with an iron based binder, which is expected to bridge the gap between high speed steels and conventional cemented carbides. Physical and mechanical properties have been measured and they show that the material can work at higher speeds than HSS in turning/form grooving.
TL;DR: In this paper, the formation of a specific nanostructure is dictated by the formation energy of a carbide of a metal being introduced, and using this fact one can control formation of nanostructures in WC-Co cemented carbides and purposefully change physico-mechanical properties of the latter.
Abstract: The regularities have been studied of the development of nanostructures in WC-Co cemented carbides in precipitating new dispersion phases from Co melt. Cobalt melts alloyed with Ti, Ta, Nb, Cr, Fe, Ni and Re, have been introduced into sintered specimens using the MMI-phenomenon. Three types of nanostructures which form in WC-Co carbides have been observed. It is shown that the formation of a specific nanostructure is dictated by the formation energy of a carbide of a metal being introduced. Using this fact one can control the formation of nanostructures in WC-Co cemented carbides and purposefully change physico-mechanical properties of the latter.
TL;DR: In this paper, the mechanical properties of a heavy metal with 92.5 wt.% tungsten were investigated in tension and three regions of distinct deformation characteristics exist.
Abstract: The mechanical properties of a heavy metal with 92.5 wt.% tungsten were investigated in tension. Three regions of distinct deformation characteristics exist. The low-temperature behaviour (
TL;DR: In this paper, a study on mixing methods of alloying Mo with low Re content was undertaken in order to develop a new Mo alloy, which was found to be effective for manufacturing Mo alloy containing 3 wt% Re by powder metallurgy.
Abstract: A study on mixing methods of alloying Mo with low Re content was undertaken in order to develop a new Mo alloy. The grain sizes of MoRe alloys varied with the mixing methods. It was discovered that the dry-wet mixing method was effective for manufacturing Mo alloy containing 3 wt% Re by powder metallurgy.