239results about How to "Suppress coarsening" patented technology

The present invention provides a catalyst comprising particles of one or more catalytic metals supported on a porous carrier made of one or more metal oxides, wherein the porous carrier is made of an oxide containing a rare earth oxide, and that the catalytic metal particles are made of one or more transition metals or transition metal oxides having 10 to 50000 atoms. In the present invention, cluster-like catalyst particles are supported on a specific carrier. The catalyst of the present invention maintains desirable activity while changing the morphology of catalyst particles by the atmosphere of the catalyst.

The present invention provides an aluminum alloy forging material having enhanced strength, toughness, and corrosion resistance, and a method of producing the material. An aluminum alloy forging material 1 produced with specified components under specified conditions has an arm portion 2 including a relatively narrow and thick peripheral rib 3 and a thin and relatively wide central web 4 having a thickness of 10 mm or less and having a substantially H-shaped sectional form. In a width-direction section of a maximum stress producing site of the rib 3a, the density of crystals observed in the structure of a sectional portion 7 where the maximum stress is produced, the spacing of grain boundary precipitates and the size and density of dispersed particles observed in the structure of a sectional portion 8 including a parting line, the recrystallization ratio observed in each of the sectional portions 7 and 8 of the rib, and the recrystallization ratio observed in a sectional portion 9 of the web 4a adjacent to the sectional structure of the rib 3a in the width direction are defined for enhancing the strength, toughness, and corrosion resistance of the aluminum alloy forging material.

The invention discloses a preparation method for a quasi-nanostructure WC-Co (tungsten-cobalt) coating with high compactness and low decarburization, and belongs to the technical field of preparation of WC-Co coatings. The preparation method comprises the steps as follows: firstly, preparing superfine and nanometer WC-Co compound powder with average particle size of 80-400 nm; secondly, mixing the WC-Co compound powder with Cr3C2 and VC powder according to a certain ratio, carrying out ball milling and drying to obtain mixed powder, granulating, and carrying out heat treatment; and thirdly, sieving for grading, combining into spraying powder with special particle size distribution, and spraying by adopting supersonic flame spraying equipment. The quasi-nanostructure WC-Co coating prepared by the method has the characteristics of high compactness and low decarburization.

The invention provides an aluminum alloy substrate used for magnetic discs, and a method of manufacturing the same. Even if an aluminum alloy substrate is heated to be as high as 500 DEG C, worsening of smoothness and thickening of crystalline grains are prevented. The aluminum alloy substrate comprises 3.5% to 6% by mass of Mg, balance being Al and unavoidable impurities. The variable quantity of the smoothness of the aluminum alloy substrate before and after heating within 10 seconds at a tempetature of 500 DEG C is below 5um, and the variable quantity of the average grain diameter of the aluminum alloy substrate before and after heating within 10 seconds at a tempetature of 500 DEG C is below 10um. According to the method of manufacturing the aluminum alloy substrate used for magnetic discs, pack annealing of the aluminum alloy substrate used for magnetic discs includes the steps of holding the substrate for more than two hours at a temperature of more than 350 DEG C under a condition that the temperature rises into over 350 DEG C at a speed of 2 DEG C per minute, and cooling at a cooling speed of below 2 DEG C per minute.

A catalyst for purifying an exhaust gas includes a composite oxide support and a platinum structural layer. The composite oxide support has a spinel structure expressed by M.Al2O4 in which M is an alkaline-earth metal. The platinum structural layer is formed on a surface of the composite oxide support and includes a matrix composed mainly of an alkaline-earth metal oxide in which platinum clusters are dispersed uniformly. A composite oxide layer can be interposed between the composite oxide support and the platinum structural layer. Also disclosed is an optimum process for producing the catalyst.

The invention discloses a continuous brazing composite aluminum-based brazing wire applying nanometer aluminum trioxide and a preparation method of the continuous brazing composite aluminum-based brazing wire applying the nanometer aluminum trioxide. The continuous brazing composite aluminum-based brazing wire applying the nanometer aluminum trioxide is composed of an aluminum-based brazing filler metal core material with a groove formed in the outer surface, a no-corrosive flux used for aluminum and applied in the peripheral groove of the core material in a wrapping manner, and a coating layer sprayed on the surface of the composite brazing flux. The obtained product is excellent in material performance, easy to machine and form, good in brazing process performance, capable of fully adapting to efficient and continuous brazing and excellent in brazing connector performance.

A flooded-type lead-acid battery in which charging is intermittently carried out in a short period of time and high-rate discharge to a load is carried out in a partial state of charge, wherein the charge acceptance and service life characteristics under PSOC are improved by using a positive plate in which the total surface area of the positive active material per unit of the plate pack volume is set in a range of 3.5 to 15.6 m²/cm³; a negative plate with improved charge acceptance and service life performance obtained by adding a carbonaceous electrically conductive material, and a formaldehyde condensate of bisphenol and aminobenzene sulfonic acid to the negative active material; and a separator formed from a nonwoven in which a surface facing the negative plate is composed of material selected from glass, pulp, and polyolefin.

The invention relates to a preparation method of a cathode of a low-medium temperature solid oxide fuel cell, belonging to the technical field of fuel cells. The preparation method comprises the following steps of: preparing a cathode layer chief source by spraying cathode slurry on an electrolytic substrate and drying at the temperature of 100-400 DEG C; and then sintering at 800-1300 DEG C in an air environment for 2-10 hours so as to obtain the cathode of the fuel cell, wherein temperature rise rate is 5-20 DEG C/minute. The invention solves the problems of overhigh oxygenic concentration polarization and higher cathodic polarization impedance which are caused by difficult structure control, poor preparation repeatability and slower oxygenic cathodic transmission of a cathode layer of the prior common low-medium temperature solid oxide fuel cell and prepares the cathode layer which has specific lamellar structure, needs no template and can be prepared easily and repeatedly by selecting a powder synthesis process, calcining temperature and temperature rise rate, thereby obviously enhancing the cathode performance.

The invention provides a narrow-hardenability pinion steel which comprises the following components in percentage by weight: 0.18%-0.22% of C, 0.20%-0.30% of Si, 0.90%-1.15% of Mn, less than or equal to 0.030% of P, less than or equal to 0.030% of S, 1.00%-1.35% of Cr, 0.04%-0.08% of Ti, 0.004%-0.005% of B, 0.025%-0.038% of W, less than or equal to 11.5*10<-6> of [O], less than or equal to 1.5*10<-6> of [H], 35*10<-6>-45*10<-6> of [N] and the balance of Fe and inevitable impurities. The invention provides a preparation method of the narrow-hardenability pinion steel. The preparation method comprises the following steps: 1) primary smelting based on a top-bottom blowing converter; 2) ladle deoxidizing and alloying; 3) LF (ladle furnace) refining; 4) RH refining; and 5) continuous casting. Compared with the prior art, the narrow-hardenability pinion steel provided by the invention has the characteristics of better wear resistance and high temperature resistance, higher hardenability andnarrower jominy hardenability.

The invention discloses a titanium-doped alpha-iron oxide photo-anode, and a preparation method and an application thereof. The method comprises the steps: coating the surface of a beta-FeOOH membrane with a titanium source solution, forming a TiO2 layer during high temperature annealing, and inhibiting grain coarsening of alpha-iron oxide; at the same time, in the process, diffusing titanium ions to the interior of alpha-iron oxide crystal lattices to realize titanium doping; and after annealing, using a hydrogen peroxide aqueous solution to remove the TiO2 layer, and thus obtaining the titanium-doped alpha-iron oxide photo-anode. The photo-anode has small particle size which is 30 nm-40 nm; the maximum photocurrent density can reach 3.62 mA/cm<2> under a 300 W xenon lamp light source and at the bias of 1.23 V[RHE]; compared with a un-doped alpha-iron oxide photo-anode without introduction of the TiO2 layer, the photocurrent is increased by 5 times, and a positive shift phenomenon of initial potential is not generated.

Provided is a rare-earth magnet containing no heavy rare-earth metals such as Dy or Tb in a grain boundary phase, has a modifying alloy for increasing coercivity (in particular, coercivity under a high-temperature atmosphere) infiltrated thereinto at lower temperature than in the conventional rare-earth magnets, has high coercivity, and has relatively high magnetizability, and a production method therefor. The rare-earth magnet RM includes a RE-Fe—B-based main phase MP with a nanocrystalline structure (where RE is at least one of Nd or Pr) and a grain boundary phase BP around the main phase, the grain boundary phase containing a RE-X alloy (where X is a metallic element other than heavy rare-earth elements). Crystal grains of the main phase MP are oriented along the anisotropy axis, and each crystal grain of the main phase, when viewed from a direction perpendicular to the anisotropy axis, has a plane that is quadrilateral in shape or has a close shape thereto.

A process for producing a combustor structural member, the process comprising a plate-like assembly formation step of brazing a first plate-like member formed from a heat-resistant alloy, and a second plate-like member formed from a heat-resistant alloy and having a plurality of fins on the surface, with the second plate-like member positioned with the fins facing the first plate-like member, by interposing a brazing filler metal comprising a melting point lowering element between the two plate-like members, thereby forming a plate-like assembly, a press molding step of press molding the plate-like assembly to form a combustor structural member of the desired shape, a strain location identification step of identifying, in accordance with the shape of the combustor structural member, strain locations where the strain generated during the press molding step exceeds a predetermined value, a localized heating step of performing localized heating of the locations within the plate-like assembly corresponding with the strain locations identified in the strain location identification step, and a cold press molding step, which is performed as the above press molding step and comprises subjecting the plate-like assembly to cold press molding with the temperature of the heated locations corresponding with the strain locations maintained at a desired temperature.

To contribute to an improvement in a dezincification resistance of a copper alloy, focusing attention on a relation between a dezincification resistance of a copper alloy and the crystal grain size of an α phase, and the specific object is to provide a method of producing a hot forged product using a lead-free brass capable of ensuring corrosion resistances such as a prescribed dezincification resistance and the like even at sites of different thickness and shape, a hot forged product, and a wetted product such as a valve and a water faucet, molded using the same. A method of producing a hot forged product using a brass, comprising heat-treating a raw material to be subjected to forging work using a brass having a composition containing at least 59.2 to 63.0% by mass of Cu, 1.00 to 2.00% by mass of Sn and 0.05 to 0.25% by mass of Pb and containing the residue composed of Zn and inevitable impurities at a heating rate of 5.2° C./s or more from 350° C. until reaching the forging temperature.

The invention belongs to the technical field of metal material additive manufacturing, and discloses a stirring friction additive manufacturing device with cooling applying. The stirring friction additive manufacturing device comprises a bottom plate, wherein a first base and a second base are correspondingly and fixedly assembled at the top of the bottom plate, a gap is reserved between the firstbase and the second base, and a test plate for additive is placed in the gap; a cushion plate is arranged at the bottom of the test plate for the additive, and grooves are formed in the surfaces, incontact with the test plate for the additive, of the first base and the second base; water cooling blocks are connected into the grooves in an inserted mode, the second base is provided with air cylinders for clamping the test plate for the additive, and air cylinder push rods are disposed perpendicular to the side surface of the test plate for the additive; and a pressure roller and a stirring head are further arranged at the top of the test plate for the additive. The stirring friction additive manufacturing device applies cooling on an existing stirring friction additive manufacturing technology, the thermal influence of the stirring and friction processing thermal cycle on the completed additive part is effectively reduced, and coarsening of a fine uniformity equiaxial crystal structure of an additive area and second phase particles are suppressed to obtain an additive member with a uniform structure and excellent performance.

The invention discloses a laser-magnetic field compound melt brazed welding method for an aluminum alloy/steel. The method comprises the following steps: cleaning and fixing the aluminum alloy and a steel plate to be overlapped; selecting laser energy according to needed welding thickness and selecting a zinc-aluminum alloy welding stick as filling metal; and controlling the wire feeding velocityand parameters of an alternating magnetic field to form a welding structure in zigzagged connection on an overlapped face of the aluminum alloy and the steel plate. By regulating the shape of a melt brazed joint by means of a synergistic effect of laser and magnetic field, the thickness of a brittle intermetallic compound at the interface is regulated by precisely controlling the laser ray energy,and meanwhile, solute segregation in a welding joint area and an interface layer is inhibited by means of action of the alternating magnetic field and tissues in the welding joint area and on the interface are refined, so that thickness, tissues and shape of the brittle intermetallic compound at the interface are controlled effectively, and a dissimilar alloy welding joint good in formation and performance is obtained.

The invention discloses a homogenization thermal-treatment method for an ultra-large semi-continuous cast round ingot and relates to the technical field of aluminum alloy processing. The method comprises the following concrete steps: (1) heating the round ingot to the temperature of 180 DEG C at a temperature rising speed below 15 DEG C/h; (2) heating the round ingot to the temperature of 520 to 535 DEG C from the temperature of 180 DEG C at a temperature rising speed of 60-90 DEG C/h, and keeping the temperature for 30h to 80h at the temperature of 520 to 535 DEG C; (3) cooling the round ingot to the temperature of 360 DEG C from the temperature of 520 t0 535 DEG C at a temperature descending speed below 60DEG C/h; (4) cooling the round ingot to the temperature of 130 DEG C from the temperature of 360 DEG C at a temperature descending speed of 80 to 200 DEG C/h; (5) cooling the round ingot to room temperature from the temperature of 130 DEG C. According to the characteristics of the ultra-large semi-continuous cast round ingot, the method disclosed by the invention can be used for fully eliminating dendritic structures and low-melting-point eutectic structures, also enabling the elements such as zirconium, manganese and vanadium to be dispersed and distributed uniformly and guaranteeing the deformation processing structures in the later period and the final comprehensive performances of products.

Provided is a copper-based sliding material including a steel back-metal layer and a Cu alloy layer. The Cu alloy layer contains, by mass %, 10 to 30% of Bi, 0.5 to 5% of an inorganic compound, and the balance being Cu and inevitable impurities. The Cu alloy layer may further contain 0.5 to 5% of Sn and/or at least one element selected from the group consisting of Ni, Fe, P and Ag in a total amount of 0.1 to 10%. The inorganic compound has an average particle size of 1 to 5 μm and a specific gravity of 70 to 130% relative to the specific gravity of Bi. Bi phase is formed in the Cu alloy layer in an average particle size of 2 to 15 μm, and the Bi phase is dispersed in the Cu alloy layer and isotropic.

The invention provides a preparation method for a carbon nanotube-alumina mixed reinforced magnesium aluminum alloy composite and relates to an alloy containing non-metallic fiber or whiskers, wherein the alloy is prepared through molten metal, fiber or whisker and particle impregnation, a carbon nanotube grows on spherical nanometer alumina and aluminum particles in situ through a floating catalyst method, and an in-situ composite carbon nanotube-alumina reinforced phase and an in-situ composite carbon nanotube-aluminum mixed reinforced phase are prepared. By the adoption of the method for preparing the carbon nanotube-alumina mixed reinforced magnesium aluminum alloy composite through a pressure impregnation process, the defects that the synthesis effect of the carbon nanotube is poor, the diffusion effect in a magnesium base is poor, the structural damage is likely to happen, the wettability of a reinforced phase-base interface is poor, the weak interface bonding is likely to happen, a composite reinforced phase is not suitable for being used as the reinforced phase of the magnesium-based composite due to the size or the structure, and consequently the excellent reinforcement effect of the carbon nanotube cannot be fully played in the prior art are overcome, and the defect that the comprehensive mechanical property of the magnesium-based composite is low is overcome.

Non-heat treated steel for soft-nitriding to form parts having high fatigue strength and excellent bend leveling property even in a case of applying soft-nitriding without thermal refining, comprising, by mass %, C: 0.30 to 0.45%, Si: 0.1 to 0.5%, Mn: 0.6 to 1.0%, Ti: 0.005-0.1% and N: 0.015 to 0.030%, and the balance Fe and impurities, having a mixed microstructure of bainite and ferrite whose bainite fraction is 5 to 90% or having a mixed microstructure of bainite, ferrite and pearlite whose bainite fraction is 5 to 90%, the steel could contain one or more of elements of Nb: 0.003 to 0.1% Mo: 0.01 to 1.0%, Cu: 0.01-1.0%, Ni: 0.01 to 1.0%, B: 0.001 to 0.005%, S: 0.01 to 0.1%, and Ca: 0.0001 to 0.005.