Abstract:
A powder-metallurgy produced tool steel article of a hot worked, fully dense, consolidated mass of prealloyed particles of a tool steel alloy having a sulfur content within the range of 0.10 to 0.70 weight percent and a maximum sulfide size below about 15 microns.
Abstract:
A process is disclosed for producing non-evaporable getter materials having good mechanical strength, high porosity and improved gas sorption rate, including mixing a metallic getter element, one or more getter alloys and a solid organic compound, with all components being in the form of powders having specific particle sizes. The thus obtained mixture is subjected to compression at a pressure lower than 1000 Kg/cm 2 and sintered at a temperature between 900 and 1200°C for a time between 5 minutes and 1 hour. The thus obtained getter material is used to produce getter bodies shaped as pellets, sheets or discs having an improved mechanical strength with respect to similar bodies obtained by a getter material of known type having comparable porosity values.
Abstract:
A hydrogen absorption alloy with a high percentage of alloy is economically produced by the following method: (1) placing two or more kinds of fine metal particles M such as Mg and Ni adapted to form a hydrogen absorption alloy by alloying together with milling balls B in mill pots (21) of a high speed ball mill; (2) providing the internal part of the mill pots with a non-oxidising atmosphere; and (3) applying a composite milling acceleration ratio G of at least 30 to the internal part of each mill pot and setting the angular velocity ratio R of the revolution of the main shaft to the rotation of each mill pot to 1.9 or less, the composite milling acceleration ratio G being expressed by G= a max/g = (ω₁)²/ [ 2g (K+N)(1+R)² ] where G : composite milling acceleration ratio; a max : composite milling acceleration (m/s²); g : acceleration of gravity (m/s²); ω₁ : angular velocity of revolution of the main shaft (1/S); K : revolutional diameter (m); N : internal diameter of mill pot (m); ω₂ : relative angular velocity of rotation of each mill pot with respect to the revolution of the main shaft (1/s); and R : ω₂/ω₁.
Abstract:
The invention provides a process for producing sintered alloy steel with excellent corrosion resistance, which comprises step (1) of mixing powdery stainless steel with a binder and, after molding, removing the binder from the molding by heating, step (2) of sintering the molding under a reduced pressure of 30 Torr or less, and step (3) of resin- tering it in a non-oxidative atmosphere under substantially ordinary pressure at temperatures higher than that of the foregoing steps (1) and (2). The invention also provides a sintered alloy steel with excellent corrosion resistance, which has a stainless steel composition and a density ratio of 92 % or more and maximum pore size of voids existing in the structure of 20 µm or less, and in which the Cr content of the surface of the sinter in an as-sintered state is 80 % or more of that of the interior of the sinter.
Abstract:
A method for fabricating a metal foam component from an aerogel containing a polymer and nanoparticles is disclosed. The method may comprise: 1) exposing the aerogel to a reducing condition at an elevated temperature for a reaction time to provide a metal foam; and 2) using the metal foam to fabricate the metal foam component. At least one of the elevated temperature and the reaction time may be selected so that at least some ligaments of the metal foam have a desired ligament diameter or at least some pores of the metal foam have a desired pore size. The desired ligament diameter may be less than about one micron and the component may be a component of a gas turbine engine.
Abstract:
Provided are a cemented carbide having excellent plastic deformation resistance and a cutting tool in which the cemented carbide is used as a substrate. A cemented carbide includes a hard phase containing tungsten carbide particles and a binder phase containing, as a main component, an iron-group element, wherein the formula B/A ‰¤ 0.05 is satisfied, where A represents the number of the tungsten carbide particles, and B represents the number of tungsten carbide particles whose number of contact points with other tungsten carbide particles is 1 or less. Preferably, the iron-group element includes cobalt, and the cobalt content in the cemented carbide is 8% by mass or more. Preferably, the tungsten carbide particles have an average particle diameter of 3 µm or more.
Abstract:
A permanent magnet is expressed by a composition formula: R p Fe q M r Cu t Co 100-p -q-r-t . The magnet includes: a crystal grain including a matrix; and a grain boundary phase. The matrix has cell phase having a Th 2 Zn 17 crystal phase, a cell wall phase dividing the cell phase, and a plurality of Cu high-concentration phases. An area ratio of Cu high-concentration phases to the matrix is not less than 0.2% nor more than 5.0%. In a 3 µm radius circle centered at a center of gravity of at least one of the Cu high-concentration phases, an average number of other Cu high-concentration phases is not less than 3 nor more than 15.
Abstract:
This invention concerns a selective laser solidification apparatus. The apparatus comprises a powder bed (104) onto which a powder layer can be deposited, a gas flow unit for passing a flow of gas over the powder bed (104) along a gas flow direction (118), a laser scanning unit (106) for scanning a laser beam over the powder layer to selectively solidify at least part of the powder layer to form one or more objects and a processing unit (131). The processing unit 131 selects a scanning sequence of the laser beam based on the gas flow direction (118). The invention also concerns a method for selecting a scanning sequence.
Abstract:
A non-aqueous electrolyte secondary battery containing an alloy particle capable of absorbing and desorbing lithium in the negative electrode has a short cycle life and is insufficient in high-rate discharge characteristics, since the alloy particle is pulverized during charge/discharge cycles. In order to solve this problem, a negative electrode is employed, which comprises an alloy particle containing: at least two selected from the group consisting of metal elements and semimetal elements; oxygen; and nitrogen. It is preferred that the alloy particle have a phase A capable of electrochemically absorbing and desorbing lithium ion and a phase B having lithium ion conductivity or lithium ion permeability and that the phase B contain larger amounts of oxygen and nitrogen than the phase A.
Abstract:
The invention relates to a cermet material comprising a first phase MAX having the general formula Ti n+1 AlC n and a second intermetallic phase having the general formula Ti x Al y , where n equals 1 or 2, x is between 1 and 3, y is between 1 and 3, and x + y ≤ 4. The proportion by volume of the first phase in the material is between 70% and 95%. The proportion by volume of the second phase in the material is between 30% and 5%. The void ratio is less than 5%.