Methods for fabricating an interconnect for a fuel cell stack that include providing a protective layer over at least one surface of an interconnect formed by powder pressing pre-alloyed particles containing two or more metal elements and annealing the interconnect and the protective layer at elevated temperature to bond the protective layer to the at least one surface of the interconnect.

A steel having high mechanical properties, characterized in that it has the following composition by weight: 12% to 25 % Nickel; 7.4% to 20 % Cobalt; 3% to 11% Molybdenum; 0.2% to 2.21% addition elements, the remainder being iron, the structure of the material including a combination of fine grains and ultrafine grains, the so-called fine grains having a grain size of between 1.2 micrometers and 3 micrometers and the so-called ultrafine grains having a grain size of between 0.2 and 1 micrometer, the proportion of ultrafine grains being between 55 % and 65 %, and a process for manufacturing the steel.

The present disclosure is directed at methods of preparing rare earth-based permanent magnets having improved coercivity and remanence, the method comprising one or more steps comprising: (a) homogenizing a first population of particles of a first GBM alloy with a second population of particles of a second core alloy to form a composite alloy preform, the first GBM alloy being substantially represented by the formula: AC.sub.bR.sub.xCo.sub.yCu.sub.dM.sub.z, the second core alloy being substantially represented by the formula G.sub.2Fe.sub.14B, where AC, R, M, G, b, x, y, and z are defined; (b) heating the composite alloy preform particles to form a population of mixed alloy particles; (c) compressing the mixed alloy particles, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization and inert atmosphere, to form a green body; (d) sintering the green body; and (e) annealing the sintered body. Particular embodiments include magnets comprising neodymium-iron-boron core alloys, including Nd.sub.2Fe.sub.14B.

A characterization method of an oxide dispersion-strengthened (ODS) iron-based alloy powder is provided. The characterization method comprises separating the strengthening phases from the powder matrix through electrolysis, and analyzing and characterizing the strengthening phases using an electron microscope.

A characterization method of an oxide dispersion-strengthened (ODS) iron-based alloy powder is provided. The characterization method comprises separating the strengthening phases from the powder matrix through electrolysis, and analyzing and characterizing the strengthening phases using an electron microscope.

A multi-scale and multi-phase dispersion strengthened iron-based alloy, and preparation and characterization methods thereof are provided. The alloy contains a matrix and a strengthening phase. The strengthening phase includes at least two types of the strengthening phase particles with different sizes. A volume of the two types of the strengthening phase particles with different sizes having a particle size less than or equal to 50 nm accounts for 85-95% of a total volume of all the strengthening phase particles. The matrix is a Fe—Cr—W—Ti alloy. The strengthening phases include crystalline Y.sub.2O.sub.3 phase, Y—Ti—O phase, Y—Cr—O phase, and Y—W—O phase. The characterization method comprises electrolytically separating the strengthening phases in the alloy, and then characterizing by using an electron microscope. The tensile strength of the prepared alloy is more than 1600 MPa at room temperature, and is more than 600 MPa at 700° C.

A method for manufacturing a sintered component includes a step of making a green compact having a relative density of at least 88% by compression-molding a base powder containing a metal powder into a metallic die, a step of machining a groove part having a groove width of 1.0 mm or less in the green compact by processing groove with a cutting tool, and a step of sintering the green compact in which the groove part is formed after the step of forming the groove part.

A hopper and method for transferring raw material, which can prevent segregation due to the impact caused by falling of the raw material powder when different types of raw material powders are transferred. The hopper for a raw material powder according to one embodiment of the present disclosure includes: a hopper body having an inner space in which the raw material powder is stored and including an outlet which is formed through the lower end thereof and through which the raw material powder is discharged; a transfer pipe to which the raw material powder discharged through the outlet is transferred and which has a region, through which the raw material powder is transferred, divided into a plurality of regions; and a slide gate unit disposed between the outlet and the transfer pipe to open or close the transfer pipe while adjusting a degree of opening of the transfer pipe.

Methods for fabricating an interconnect for a fuel cell stack that include providing a protective layer over at least one surface of an interconnect formed by powder pressing pre-alloyed particles containing two or more metal elements and annealing the interconnect and the protective layer at elevated temperature to bond the protective layer to the at least one surface of the interconnect.

Methods for fabricating an interconnect for a fuel cell stack that include providing a protective layer over at least one surface of an interconnect formed by powder pressing pre-alloyed particles containing two or more metal elements and annealing the interconnect and the protective layer at elevated temperature to bond the protective layer to the at least one surface of the interconnect.