Abstract:
A process for producing a dispersed-oxide-containing alloy in which oxide particles of one or more additive metals are dispersed in a matrix metal. The process, which is for producing a dispersed-oxide-containing alloy, comprises (a) a step in which a powder or wire of an alloy comprising a matrix metal and one or more additive metals is produced, (b) a step in which the alloy powder or wire is introduced into a high-energy ball mill together with water and the contents are agitated to thereby oxidize the additive metals contained in the alloy powder with water and form dispersed particles, and (c) a step in which the alloy powder or wire after the oxidization is shaped and solidified. It is useful especially for the production of a dispersed-oxide-containing alloy in which the free energy of oxide formation of the matrix metal is higher than the standard free energy of formation of water and the free energy of oxide formation of the additive metals is lower than the standard free energy of formation of water.
Abstract:
The invention concerns a method and a device for preparing nuclear metal or metal alloy particles comprising: means (4) for preparing by melting a fluid mass of the metal or of the alloy; means (12) for providing the fluid mass of the metal or of the metal alloy in the form of a jet of molten metal or metal alloy; means (1-7) for driving a hardening fluid in centrifugal rotation and in spraying particles of the jet of molten metal or metal alloy, and for rapidly hardening the particles; means (16-19) for melting the nuclear metal or the metal alloy under an atmosphere of inert gas, and means for enclosing the jet of molten metal or metal alloy with an inert gas envelope until it is hardened.
Abstract:
The present invention aims at providing an oxide-dispersed platinum material which can be stably used at high temperatures and has excellent weldability. The present invention provides an oxide-dispersion-strengthened platinum material in which dispersed particles made from a metallic oxide of an additive metal are dispersed in a matrix made from platinum or a platinum alloy, characterized in that the concentration of oxygen in the material except oxygen bound to the additive metal is 100 ppm or lower. The platinum material according to the present invention has preferably an average diameter of the dispersed particles of 0.2 µm or smaller, and an average interparticle distance of 0.01 to 2.7 µm. The platinum material also preferably has the concentration of the dispersed particles in an amount of 0.01 to 0.5 wt%, and an oxidation rate of the additive metal of 50 to 100%.
Abstract:
A powder for forming a R-Fe-B bonded magnet, wherein an R compound, such as an R oxide, an R carbide, an R nitride or an R hydride, which is contained in a raw material powder such as a super rapidly cooled powder or a hydrogen treated powder (HDDR powder) and reacts with water vapor to change into R(OH)3, has been converted to a R hydroxide R(OH)3 being stable in the air by subjecting the raw material powder to a heat treatment in an atmosphere of a pressured water vapor. The powder for forming an R-Fe-B bonded magnet is free from the generation of a white powder in the surface of or inside a bonded magnet formed from the powder, and accordingly, is free from the occurrence of cracking, chipping, swelling or the like in the bonded magnet caused by volume expansion of a white powder. Thus, the above powder can be used for preparing an R-Fe-B bonded magnet which is free from the white powder which has been observed in a conventional R-Fe-B bonded magnet in the use for a long period of time and is reduced in the occurrence of defects such as cracking, chipping, swelling and the like.
Abstract:
Provide a method and apparatus for producing, in an economical manner, metal powder offering high purity and comprising uniform particle shape and size. Produce metal powder of titanium metal, etc., using an apparatus that comprises a power supply for high-voltage/current discharge, a feeder of metal electrode made of titanium metal, etc., a high-voltage discharge generator equipped with a metal electrode made of titanium, etc., and its counter electrode, a water tank, a water inlet, an outlet for produced metal dispersion solution containing titanium metal, etc., a discharge pump, and an adjunct device for separating/recovering metal powder of titanium metal, etc., from the metal dispersion solution containing titanium metal, etc.
Abstract:
The present invention concerns a method of preparing PM products by high velocity compaction of iron or iron-based powers having irregular powder particles.
Abstract:
Alloy steel powders capable of obtaining high strength in a sintered state and having excellent compacting compressibility and methods of manufacturing a sintered body. The alloy steel powder comprises, by wt%, about 0.5 - 2% of Cr, not greater than about 0.08% of Mn, about 0.1 - 0.6% of Mo, about 0.05 - 0.5% of V, not greater than about 0.015 of S, not greater than about 0.2% of O, and the balance being Fe and incidental impurities. The alloy steel powder is compacted and sintered at a temperature at about 1100 - 1300°C and then cooled at a cooling rate no higher than about 1°C/s in a temperature range of from about 800°C to 400°C. The alloy steel powder can contain Nb and/or Ti and one or more of Co, W and B. Additionally, Ni powder and/or Cu powder may be adhered and dispersed onto the surface of the alloy steel powder.
Abstract:
The invention relates to a binder system, characterized in that the binder system consists of: (a) 30 to 95 per cent by weight of a water-soluble polyethylene glycol (PEG), and (b) 70 to 5 per cent by weight of a polyvinyl butyral (PVB). The invention also relates to a method for producing a product by means of PIM or powder extrusion using the binder system according to the invention, in which, in order to remove the binder system from a green product, firstly at least 70% of the PEG is removed by means of a solvent which substantially comprises water, and holding the product at a temperature in a range from 10 to 40°C for 8 to 100 hours.