Government of the United States of America, as Represented by the Secretary of Commerce

Other

Materials Innovation, Inc.

The United States of America as Represented by the Secretary of

Micro Properties Inc.

Christian E Johnson

David S Lashmore

Glenn L Beane

David R Kelley

Frederick C Eichmiller

Moshe P Dariel

Menahem B Ratzker

Elaine Soltani

Anthony A Guiseppetti

Anthony A Giuseppetti

Robert S Polvani

Jasper L Mullen

Gery R Stafford

A metallic composite solid, containing alloys and/or intermetallics, is formed by compacting at moderate pressure a mixture of powder particles, foils or sheets at a temperature close to room temperature, well below the melting temperature of the constituent components and without the addition of low melting metals such as mercury, indium or gallium acting as a sintering agent. This low temperature consolidation of the powder mixture is enhanced by having the surface oxide of the powder particles removed, prior to consolidation, and/or by coating the particles with an oxide-replacing metal such as silver or gold. The coating process may be replacement reactions, autocatalytic reduction or electrolytic reduction. The composite formation is assisted by the addition of a liquid acid such as fluoroboric acid, sulfuric acid, fluoric acid, adipic acid, ascorbic acid, or nitric acid. A preferred embodiment of the process for metal solid composite formation is a process for forming dental restorative materials at ambient temperatures and under pressure exerted by manual dental instrumentation.

Acid assisted cold welding and intermetallic formation and dental applications thereof

A method for coating particulate substrate materials is provided which comprises (a) combining particles and an electrolyte in an imperforate container; (b) vibrating the container to generate a fluidized bed of particles in the electrolyte; and (c) electrochemically depositing a coating on the particles from reactants in the electrolyte. An apparatus for coating particles is also provided which comprises an imperforate container for receiving particles to be coated and an electrolyte and a device for generating a fluidized bed in the container, the device being operatively associated with the container.

Method for electrochemical fluidized bed coating of powders

A method for the chemical precipitation of metallic silver powder employs a two solution technique in which a solution of a tin salt and a solution a silver salt are mixed in the presence of an inorganic or organic acid, alumina, an anionic surfactant, and a colloid to form a precipitation solution at a temperature and pH suitable to effect the chemical precipitation of silver. Almost 80% by weight of the precipitated powder agglomerate is less than 25 .mu.m in diameter, and the individual powder particles which compose the agglomerate range in size from 0.2 to 2.0 .mu.m. In addition to the favorable size distribution, silver particles precipitated in the presence of a gelatin colloid can be used with a minimal amount of sieving so that little work hardening is imparted to the particles. The powder can be annealed at a temperature of up to 750.degree. C. for two hours in air with minimal sintering, and the acid-assisted hand consolidation of powder produced according to the present technique is capable of producing silver compacts which are nearly 80% dense. Advantageously, a hand consolidated silver compact which comprises the powder of the present invention equals or exceeds the transverse rupture strength, shear strength, creep, toughness, corrosion resistance, microleakage, and wear properties of conventional silver amalgam.

Method for chemical precipitation of metallic silver powder via a two

Acid assisted cold welding and intermetallic formation

Methods for electrodepositing a metal-carbon coating on a substrate comprng immersing the substrate in an aqueous electrolyte, and passing a sufficient current through the electrolyte to effect electrolyte deposition of a metal-carbon alloy on the substrate. The aqueous electrolyte comprises from about 0.2 to about 0.6 mol/l of metal ions selected from the group consisting of iron, nickel, nickel-tungsten mixture and cobalt-tungsten mixture, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.

Methods and electrolyte compositions for electrodepositing metal-carbon

Acid assisted cold welding and intermetallic formation and dental

Electrochemical fluidized bed coating of powders

Methods for electrodepositing a chromium coating on a substrate comprising mmersing the substrate in an aqueous electrolyte, and passing a sufficient current through the electrolyte to effect deposition of a chromium coating on the substrate. The aqueous electrolytes comprise from about 0.2 to about 0.6 mol/l of trivalent chromium ions, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.

Methods and electrolyte compositions for electrodepositing chromium

A device and method are described for measuring and evaluating mechanical properties such as microhardness of a material. The present invention conveniently incorporates commercially available hardness testing equipment but modifies it to permit continuous evaluation and measurement of the displacement of the stylus used to indent the sample being tested. By simultaneously monitoring displacement, load applied to the stylus and time values relating to the mechanical properties of the material such as wear, fatigue and tensile strength are obtained.

Automated device for determining and evaluating the mechanical

The invention provides a method of producing an ultra-black surface coating, having an extremely high light absorption capacity, on a substrate, such as a metal, ceramic, glass, or plastic, the blackness being associated with a unique surface morphology consisting of a dense array of microscopic pores etched into the surface, as well as the resulting coated substrate. The ultra-black surface, which has a spectral reflectance on the order of about from 0.5 to 1.0% at wavelengths of light of about from 320 to 2140 nanometers, finds use as a solar collector in the field of solar energy.

Ultra-black coating due to surface morphology

The invention provides a method of producing an ultra-black surface coating, having an extremely high light absorption capacity, on a substrate, such as a metal, ceramic, glass, or plastic, the blackness being associated with a unique surface morphology consisting of a dense array of microscopic pores etched into the surface, as well as the resulting coated substrate. The method involves preparing the substrate for plating with a nickel-phosphorus alloy, as by cleaning and/or activating it, immersing the thus-prepared substrate in an electroless plating bath containing nickel and hypophosphite ions in solution until an electroless nickel-phosphorus alloy coating has been deposited on the substrate, and then removing the substrate, coated with the electroless nickel-phosphorus alloy, from the plating bath and washing and drying it. The dried substrate, coated with the electroless nickel-phosphorus alloy, is then immersed in an etchant bath consisting of an aqueous solution of nitric acid, wherein the nitric acid concentration ranges from a 1:5 ratio with distilled or de-ionized water to concentrated, until the coated surface of the substrate develops ultra-blackness, the blackness being associated with the surface morphology as described above. The resulting substrate, covered with the ultra-black coating is thereafter washed and dried. The ultra-black surface, which has a spectral reflectance on the order of about from 0.5 to 1.0% at wavelengths of light of about from 320 to 2140 nanometers, finds use as a solar collector in the field of solar energy.

Growing community of inventors

Middletown, MD, United States of America

Christian E Johnson