摘要:
A method for forming a uniform, dense electroplated coating on the surface of an article with good adhesion irrespective of the surface material and surface properties. The method is characterized in that a resin coating containing resin in which powder of a first metal is dispersed is formed on the surface of an article, a displacement plated coating of a second metal having a potential nobler than that of the first metal is formed on the resin coating surface by dipping the resin coated article in a solution containing ions of the second metal, and an electroplated coating of a third metal is formed on the displacement plated coating.
摘要:
An Si-base thermoelectric conversion material and a thermoelectric conversion element, wherein without lowering the Seebeck coefficient and electric conductivity of the Si-base thermoelectric conversion material, the heat conductivity of the material can be greatly lowered to realize a great improvement in performance index. A crystalline structure, which is a polycrystalline structure, having crystal grains of Si-rich phase and also having an added element-rich phase containing one or more added elements precipitated in the grain boundaries is formed, whereby the Seebeck coefficient becomes very high and the heat conductivity becomes low, making it possible to greatly increase the thermoelectric conversion efficiency; thus, there is provided an Si-base thermoelectric conversion material consisting mainly of Si, which is a naturally abundant element, and causing least environmental pollution. For example, the addition of C, Ge or Sn to the Si-base thermoelectric conversion material makes it possible to greatly reduce the heat conductivity without changing the carrier concentration in the Si-base material. To lower the heat conductivity, the optimum amount of addition is 5-10 atom percent. The material has a structure in which the group IV elements and addition elements added to prepare p-type or n-type semiconductors precipitate in the grain boundaries of the polycrystalline Si, whereby there is obtained a p-type or n-type semiconductor having a carrier concentration of 10 - 10 (M/m ) and a heat conductivity of 50 W/m•K or less.
摘要:
A method for producing an iron base rare earth alloy nanocomposite magnet powder, which comprises quenching by the atomizing method a molten alloy having the empirical formula represented by (Fe1-mTm)100-x-y-zQxRyTizMn , wherein T represents one or more elements selected from the group consisting of Co and Ni, Q represents at least one element selected from the group consisting of B and C, R represents at least one element selected from the group consisting of the rare earth elements and yttrium, M represents at least one element selected from the group consisting of Nb, Zr, Mo, Ta and Hf, and numbers x, y, z, m and n concerning a composition proportion satisfy 10
摘要:
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.
摘要:
A method for making a granulated powder according to the present invention includes the steps of: preparing a rare-earth alloy powder with remanent magnetization; feeding the powder onto a track 22, which is defined by a side surface 22a and a lower surface 22b that is sloped so as to decrease its height toward the side surface; and setting up vibrations on the track to give the powder kinetic energy, thereby transporting the powder along the length of the track and granulating the powder under a substantially zero magnetic field by utilizing an agglomeration force produced by the remanent magnetization of the powder and a tumbling action produced by the kinetic energy. As a result, a rare-earth alloy granulated powder, which has good flowability and good compactibility and which makes it possible to produce a magnet with excellent magnetic properties, can be obtained.
摘要:
High-melting metal layers (2), (4), (6), (8), and (10) are stacked alternately with magnetic rare-earth alloy layers (3), (5), (7), (9), (11), and (12) to form on a substrate a layered structure composed of four or more unit layers. The high-melting metal layers (2), (4), (6), (8), and (10) are made of at least one material selected from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten and each has a thickness of 5 to 50 nm. The magnetic rare-earth alloy layers (3), (5), (7), (9), (11), and (12) comprise tetragonal crystals of R2Fe14B (wherein R is neodymium and/or praseodymium) as the main constituent phase and each has a thickness of 50 to 500 nm.