Abstract:
Disclosed herein is a method and gas atmosphere for a metal component in a continuous furnace. In one embodiment, the method and gas atmosphere comprises the use of an effective amount, or about 1 to about 10 percent volume of endo-gas, into an atmosphere comprising nitrogen and hydrogen. In another embodiment, there is provided a method sintering metal components in a furnace at a one or more operating temperatures comprising: providing a furnace comprising a belt comprising a wire mesh material wherein the metal components are supported thereupon; and sintering the components in the furnace in an atmosphere comprising nitrogen, hydrogen, and effective amount of endothermic gas at the one or more operating temperatures ranging from about 1800° F. to about 2200° F. wherein the amount of endothermic gas in the atmosphere is such that it is oxidizing to the wire mesh material and reducing to the metal components.
Abstract:
A chromium-iron alloy comprises in weight %, 1 to 3% C, 1 to 3% Si, up to 3% Ni, 25 to 35% Cr, 1.5 to 3% Mo, up to 2% W, 2.0 to 4.0% Nb, up to 3.0% V, up to 3.0% Ta, up to 1.2% B, up to 1% Mn and 43 to 64% Fe. In a preferred embodiment, the chromium-iron alloy comprises in weight %, 1.5 to 2.3% C, 1.6 to 2.3% Si, 0.2 to 2.2% Ni, 27 to 34% Cr, 1.7 to 2.5% Mo, 0.04 to 2% W, 2.2 to 3.6% Nb, up to 1% V, up to 3.0% Ta, up to 0.7% B, 0.1 to 0.6% Mn and 43 to 64% Fe. The chromium-iron alloy is useful for valve seat inserts for internal combustion engines such as diesel or natural gas engines.
Abstract:
A process for the manufacture of soft magnetic composite components is provided comprising the steps of die compacting a powder composition comprising a mixture of soft magnetic, iron or iron-based powder, the core particles of which are surrounded by an electrically insulating, inorganic coating, and an organic lubricant in an amount of 0.05 to 1.5% by weight of the composition, the organic lubricant being free from metal and having a temperature of vaporisation less than the decomposition temperature of the coating; ejecting the compacted body from the die; heating the compacted body in a non-reducing atmosphere to a temperature above the vaporisation temperature of the lubricant and below the decomposition temperature of the inorganic coating for removing the lubricant from the compacted body, and subjecting the obtained body to heat treatment at a temperature between 300° and 600° in water vapour. The invention also concerns soft magnetic composite components having a transverse rupture strength of at least 100 MPa, a permeability of at least 700, and a core loss at 1 Tesla and 400 Hz of at most 70 W/kg.
Abstract:
A method for manufacturing a hydrodynamic bearing (30) includes the following steps. First, a substrate having a surface with multiple protrusions thereon is formed. The protrusions are adapted for forming grooves in a preform. The preform, when finally processed, becomes a shaft of the hydrodynamic bearing or a bearing of the hydrodynamic bearing. Second, a feedstock of binder and powder is pushed to the surface of the substrate to form the perform on the surface of the substrate. Third, the substrate is removed from the preform. Fourth, the preform is sintered. Fifth, the preform is precision machined to obtain the shaft or the bearing, as the case may be. In the shaft or bearing, the grooves are for generating hydrodynamic pressure.
Abstract:
One provides (101) disperse ultra-nanocrystalline diamond powder material that comprises a plurality of substantially ordered crystallites that are each sized no larger than about 10 nanometers. One then reacts (102) these crystallites with a metallic component. The resultant nanowire is then able to exhibit a desired increase with respect to its ability to conduct electricity while also substantially preserving the thermal conductivity behavior of the disperse ultra-nanocrystalline diamond powder material. The reaction process can comprise combining (201) the crystallites with one or more metal salts in an aqueous solution and then heating (203) that aqueous solution to remove the water. This heating can occur in a reducing atmosphere (comprising, for example, hydrogen and/or methane) to also reduce the salt to metal.
Abstract:
A method of stabilizing lithium metal powder is provided. The method includes the steps of heating lithium metal to a temperature above its melting point, agitating the molten lithium metal, and contacting the lithium metal with a fluorination agent to provide a stabilized lithium metal powder.
Abstract:
A method of manufacturing a semiconductor material in the form of bricks or granules, includes a step of sintering powders of at least one material selected from the group consisting of silicon, germanium, gallium arsenide, and the alloys thereof so as to form said granules. The sintering step includes the steps of compacting and thermal processing the powders, and a step of purifying the semiconductor material using a flow of a gas. The gas flow passes through the porosity channels of the material.
Abstract:
A hydrodynamic bearing has a plurality of grooves (34) defined therein. The grooves are used for generating hydrodynamic pressure. Each of the grooves includes an upper branch (344) and a lower branch (342) coupled to the upper branch. The upper branch has a larger angle (β1) of divergence from the groove than that (β2) of the lower branch.
Abstract:
One provides (101) disperse ultra-nanocrystalline diamond powder material that comprises a plurality of substantially ordered crystallites that are each sized no larger than about 10 nanometers. One then reacts (102) these crystallites with a metallic component. The resultant nanowire is then able to exhibit a desired increase with respect to its ability to conduct electricity while also substantially preserving the thermal conductivity behavior of the disperse ultra-nanocrystalline diamond powder material. The reaction process can comprise combining (201) the crystallites with one or more metal salts in an aqueous solution and then heating (203) that aqueous solution to remove the water. This heating can occur in a reducing atmosphere (comprising, for example, hydrogen and/or methane) to also reduce the salt to metal.
Abstract:
Described is a method for producing high purity tantalum, the high purity tantalum so produced and sputtering targets of high purity tantalum. The method involves purifying starting materials followed by subsequent refining into high purity tantalum.