A method for producing a metal particle which includes the steps of: mixing a metal salt and a polycarboxylic acid in a liquid phase; adding a reducing agent to the resultant mixture to deposit metal particles; and drying the deposited metal particles.

Polycrystalline compacts include a polycrystalline material comprising a plurality of inter-bonded grains of hard material, and a metallic material disposed in interstitial spaces between the inter-bonded grains of hard material. At least a portion of the metallic material comprises a metal alloy that includes two or more elements. A first element of the two or more elements comprises at least one of cobalt, iron, and nickel. A second element of the two or more elements comprises at least one of dysprosium, yttrium, terbium, gadolinium, germanium, samarium, neodymium, and praseodymium. The metal alloys may comprise eutectic or near-eutectic compositions, and may have relatively low melting points. Cutting elements and earth-boring tools include such polycrystalline compacts. Methods include the formation of such polycrystalline compacts, cutting elements, and earth-boring tools.

Polycrystalline compacts include a polycrystalline material comprising a plurality of inter-bonded grains of hard material, and a metallic material disposed in interstitial spaces between the inter-bonded grains of hard material. At least a portion of the metallic material comprises a metal alloy that includes two or more elements. A first element of the two or more elements comprises at least one of cobalt, iron, and nickel. A second element of the two or more elements comprises at least one of dysprosium, yttrium, terbium, gadolinium, germanium, samarium, neodymium, and praseodymium. The metal alloys may comprise eutectic or near-eutectic compositions, and may have relatively low melting points. Cutting elements and earth-boring tools include such polycrystalline compacts. Methods include the formation of such polycrystalline compacts, cutting elements, and earth-boring tools.

Provided in one embodiment is a method of identifying a stable phase of an ordering binary alloy system comprising a solute element and a solvent element, the method comprising: determining at least three thermodynamic parameters associated with grain boundary segregation, phase separation, and intermetallic compound formation of the ordering binary alloy system; and identifying the stable phase of the ordering binary alloy system based on the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter by comparing the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter with a predetermined set of respective thermodynamic parameters to identify the stable phase; wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase.

Provided in one embodiment is a method of identifying a stable phase of an ordering binary alloy system comprising a solute element and a solvent element, the method comprising: determining at least three thermodynamic parameters associated with grain boundary segregation, phase separation, and intermetallic compound formation of the ordering binary alloy system; and identifying the stable phase of the ordering binary alloy system based on the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter by comparing the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter with a predetermined set of respective thermodynamic parameters to identify the stable phase; wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase.

The present invention addresses the problem of providing a method for producing metal microparticles in which the particle diameter and the coefficient of variation are controlled. Using at least two kinds of fluid to be processed including a fluid which contains at least one kind of reducing agent, the fluid to be processed is mixed in a thin film fluid formed between at least two processing surfaces, at least one of which rotates relative to the other, and which are disposed facing each other and capable of approaching and separating from each other, and metalmicroparticles are separated. At this time, the fluid to be processed containing one or both of the fluid which contains at least one kind of metal and/or metal compound and the fluid which contains at least one kind of reducing agent contains a water-containing polyol in which water and a polyol are mixed, and does not contain a monovalent alcohol, and the particle diameter and coefficient of variance of the separated metal microparticles is controlled by controlling the ratio of water contained in the water-containing polyol.

A method of making dispersion-strengthened alloy particles involves melting an alloy having a corrosion and/or oxidation resistance-imparting alloying element, a dispersoid-forming element, and a matrix metal wherein the dispersoid-forming element exhibits a greater tendency to react with a reactive species acquired from an atomizing gas than does the alloying element. The melted alloy is atomized with the atomizing gas including the reactive species to form atomized particles so that the reactive species is (a) dissolved in solid solution to a depth below the surface of atomized particles and/or (b) reacted with the dispersoid-forming element to form dispersoids in the atomized particles to a depth below the surface of said atomized particles. The atomized alloy particles are solidified as solidified alloy particles or as a solidified deposit of alloy particles. Bodies made from the dispersion strengthened alloy particles, deposit thereof, exhibit enhanced fatigue and creep resistance and reduced wear as well as enhanced corrosion and/or oxidation resistance at high temperatures by virtue of the presence of the corrosion and/or oxidation resistance imparting alloying element in solid solution in the particle alloy matrix.

A method of making dispersion-strengthened alloy particles involves melting an alloy having a corrosion and/or oxidation resistance-imparting alloying element, a dispersoid-forming element, and a matrix metal wherein the dispersoid-forming element exhibits a greater tendency to react with a reactive species acquired from an atomizing gas than does the alloying element. The melted alloy is atomized with the atomizing gas including the reactive species to form atomized particles so that the reactive species is (a) dissolved in solid solution to a depth below the surface of atomized particles and/or (b) reacted with the dispersoid-forming element to form dispersoids in the atomized particles to a depth below the surface of said atomized particles. The atomized alloy particles are solidified as solidified alloy particles or as a solidified deposit of alloy particles. Bodies made from the dispersion strengthened alloy particles, deposit thereof, exhibit enhanced fatigue and creep resistance and reduced wear as well as enhanced corrosion and/or oxidation resistance at high temperatures by virtue of the presence of the corrosion and/or oxidation resistance imparting alloying element in solid solution in the particle alloy matrix.

The invention relates to a rare earth based hydrogen storage alloy, represented by the general formula (I):

RE.sub.xY.sub.yNi.sub.z-a-b-cMn.sub.aAl.sub.bM.sub.cZr.sub.ATi.sub.B  (I)

wherein RE denotes one or more element(s) selected from La, Ce, Pr, Nd, Sm, Gd; M denotes one or more element(s) selected from Cu, Fe, Co, Sn, V, W. The alloy has favorable pressure-composition-temperature characteristic, high hydrogen storage capacity, high electrochemical capacity. The alloy doesn't contain magnesium element, and the preparation process of the alloy is easy and safe.

A ring molded article manufacturing method capable of reliably and efficiently producing a ring molded article in which dead metal regions are reduced, and a ring material used for producing the ring molded article, are provided. The present invention relates to the method for manufacturing a ring molded article having two convex portions which respectively protrude on both sides of the ring molded article in a direction of a center axis thereof and extend in a direction of a circumference of the ring molded article. In the manufacturing method, the ring material is placed inside two molds on which concave portions respectively corresponding to the convex portions are formed, in a condition in which the ring material is supported by a region on an outer peripheral side from an outer peripheral side corner in the concave portion of one of the two molds and a region on an inner peripheral side from an inner peripheral side corner in the concave portion of another of the two molds, the ring material is then forged so as to be pressed by the two molds in a direction of a center axis of the ring material, and the ring molded article is thus produced. In addition, the present invention relates to the ring material used for producing the ring molded article.