Technalum Research, Inc.

Boris V Farmakovsky

Navtej S Saluja

Igor V Gorynin

Julian Szekely

Karina V Kalogina

Alexander P Khinsky

Alfredo Riviere V

Alfredo V Riviere

Evgenii V Vlasov

The method for preparing a coating with a continuous compositional gradient includes introducing at least first and second powders into a plasma torch at separately controllable variable feed rates for each powder and co-depositing the at least first and second powders on the substrate and adjusting the relative feed rates of the first and second powders such that a smooth continuous compositional grading is achieved in the coating. The compositional gradient can follow a linear, exponential or variable function. A sublayer may be deposited onto the substrate prior to deposition of the compositionally graded layer. Additional materials that impart other desirable properties to the layer can be added with the layer or applied after deposition of the layer. Choice of atmosphere during deposition include vacuum, inert atmosphere, and oxidizing, carburizing and boriding atmospheres.

Method for the production of compositionally graded coatings by plasma

A metal-coated particle is prepared by providing a disintegrator apparatus with a working chamber containing counter-rotating disks equipped with teeth design to accelerate particles towards one another, providing a first material and a second metal as powders, such that the first material is harder than the second metal and introducing the first material and second metal powders into the working chamber of the disintegrator apparatus, whereby the soft second metal collides with the hard material and is coated onto the surface of the hard first material. A metal-coated metal with an intermetallic interface is prepared by introducing a first material and a second metal as powders into a disintegrator working chamber containing counter-rotating disks and teeth designed to accelerate particles towards one another. The first material harder than the second metal and is capable of reacting with the second metal to form an intermetallic compound. The disks of the disintegrator are counter-rotted so as to cause the metal powders to collide with each other, whereby the hard metal powder is mechanically coated by second metal. The rate of rotation of the counter-rotating disks are further increased in a high velocity process whereby high local temperatures generated on impact cause a reaction to occur at the first material/second metal interface to form an intermetallic compound.

Method for coating particles using counter-rotating disks

The method for preparing metal powders with a narrow particle size distribution includes providing a disintegrator with a working chamber containing counter-rotating disks equipped with teeth designed to impart high tangential velocities to particles contacting the teeth, introducing a metal melt as a liquid stream with a composition substantially corresponding to the final metal powder composition into the working chamber of the disintegrator, counter-rotating the disks, whereby the liquid stream of metal entering the chamber is broken up into small beads, which leave the surface of the teeth with high velocities, and whereby subsequent contact of the beads with the teeth of the disks further break up the liquid beads until the bead solidifies by heat loss to the disks and collecting a fine metal powder of narrow particle size distribution at the exit end of the working chamber.

Method of preparing particles with a controlled narrow distribution

A method for preparing glass-coated microwires is provided. A metal in a glass tube is superheated in a high frequency induction field, whereby the glass tube softens. A thin capillary tube is drawn from the softened glass and the glass tube fills with molten metal. The metal-filled capillary enters a cooling zone in the superheated state and the rate of cooling is controlled such that a microcrystalline or amorphous metal microstructure is obtained. The cooling zone includes a stream of cooling liquid through which the capillary passes. The microstructure of the microwire is controlled by choice of amorphisizers, cooling rate, nature of the cooling liquid, location of the cooling stream, dwell time in the cooling stream and degree of superheating and supercooling of the metal.

Method of casting amorphous and microcrystalline microwires

A multi-layered catalyst on a metal substrate and a method for its preparation is provided. The catalyst includes a substrate, an adhesive sublayer whose improved adhesion to the substrate is obtained by the formation of a diffusion layer between the substrate and adhesive layer, a catalytically active layer deposited on the adhesive sublayer characterized by a smooth compositional gradient of the catalytically active component such that the catalytically active layer ranges from substantially 0.0 wt % at the adhesive sublayer interface to substantially 100 wt % at the outermost portion of the catalytically active layer and a porous layer containing at least the catalytically active component. An activator coating can be applied to the porous layer. The catalyst is prepared by plasma spraying a thermally reactive powder onto the substrate to form the adhesive sublayer, whereby the heat generated by the thermally reactive powders causes diffusion of the sublayer into the substrate and a diffusion bonded layer is formed resulting in a strong adhesion of the sublayer to the substrate, subsequently introducing at least alumina and a second powder into a plasma torch at separately controllable variable feed rates and co-depositing alumina and the second powder, adjusting the relative feed rates of alumina and second powder into the plasma torch such that a catalytically active layer with a smooth compositional gradient is achieved, whereby the alumina content of the catalytically active layer ranges from substantially 0 wt % at the adhesive sublayer interface to substantially 100 wt % at the uppermost portion of the catalytically active layer, subsequently introducing at least alumina and an additional metal carbonate or hydroxide into the plasma torch; and co-depositing a porous layer of at least alumina and the additional metal carbonate or hydroxide, whereby the metal carbonate or hydroxide decomposes with a release of gas or vapor resulting in an outer coating with a high surface area.

Catalyst composition and a method for its preparation

The method of preparing metal-coated metals includes providing a metal powder and a disintegrator with a working chamber equipped with counter-rotating disks. At least one of said disks is made of a material softer than said metal powder. The metal powder is introduced into the working chamber and the disks of the disintegrator are counter-rotated so as to cause the metal powder to strike the disks, whereby the disk is eroded by the colliding metal particles and a coating of the eroded material is formed on the metal powder and the metal-coated metal particles are collected at the exit end of the disintegrator.

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Saint-Petersburg, Russia

Boris V Farmakovsky