Redunndant Materials, Inc.

Other

Gas Research Institute

Michael P Dunn

Michael L Dunn

Martin R Kasprzyk

Brian M Tierney

A method for bonding an electrically conductive silicon carbide structure to an electrically conductive siliconized silicon carbide structure by temporarily securing the siliconized silicon carbide structure to the silicon carbide structure; placing the silicon carbide structure with secured siliconized silicon carbide structure into an induction heating furnace having an induction coil which heats electrically conductive material in the furnace when sufficient electrical power at a frequency of from about 300 to about 1000 KC is passed through the coil; and causing sufficient electrical power at a frequency of from about 300 to about 1000 KC to be passed through the coil to raise the temperature of the siliconized silicon carbide structure and silicon carbide structure to a temperature above about 1500&#xb0; C. at the region of temporary attachment to release the attachment and cause silicon metal to flow from the siliconized silicon carbide structure into the silicon carbide structure to form a siliconized silicon carbide bond between the silicon carbide structure and siliconized silicon carbide structure.

Method for making a silicon carbide resistor with silicon/silicon carbide contacts by induction heating

An induction furnace that has a plurality of high temperature electrically conductive ceramic electrodes having no connecting electrical lead (leadless electrode). The leadless electrodes are exterior to and proximate a working furnace space. At least one metallic electrical conductor surrounds but is not connected to the ceramic electrodes and a power supply is connected to the at least one electrical conductor so that activation of the power supply creates an alternating current through the electrical conductor of sufficient energy to create an electromagnetic flux of sufficient flux density to heat the at least one ceramic electrode to a temperature in excess of about 1700&deg; C. to heat the space. A very high temperature furnace for operation in air is included within the invention wherein electrodes proximate the working furnace space are made of a high temperature, stable, electrically conductive metal oxide and at least one intermediate leadless electrode is provided sufficiently near the proximate metal oxide (e.g. zirconia) ceramic electrodes to heat the proximate metal oxide ceramic electrodes above their electrical conducting temperature so that they conducts sufficient current to maintain their own temperature. The intermediate ceramic electrodes can then be withdrawn. The invention further includes the method of heating a material to high temperature using the furnace of the invention.

Ultra high temperature rapid cycle induction furnace

A method for the manufacture of a structure from a carbide of a group IIa, group IIIa, group IVa, group IVb, group Vb, group VIb, group VIIb or group VIIIb carbon reactive element including the steps of: mixing the element with the carbon; and heating the carbon and the element to melt the element so that it reacts with the carbon to form the carbide; wherein, the carbon and element are heated by means of electromagnetic radiation having a frequency below the infrared spectrum. The method does not waste energy by unnecessary heating of the furnace or surrounding mold. The mold itself may be more stable because it is only heated by hot contained material and not by other sources of heat. Resulting formed products are not a sintered product and may approach one hundred percent of theoretical density. The carbon may be in the form of a powder that is mixed with the element or may be a porous carbon structure such as a graphite fiber mat or sheet into which the carbon reactive element is melted. When a powder is used, it is usually a graphite powder. The preferred carbides prepared in accordance with the present invention are refractory carbides. Examples of preferred carbon reactive elements for use in accordance with the present invention are boron, chromium, hafnium, iron, molybdenum, niobium, silicon, tantalum, titanium, tungsten, vanadium, and zirconium. A preferred group IIIa element for use in accordance with the present invention is boron. The most preferred element of group IVa), is silicon. Silicon carbide is hard, high melting, almost chemically inert, and has excellent dielectric properties.

Carbide material by electromagnetic processing

A method of making a ceramic tube of silicon and silicon carbide comprising the steps of covering a mandrel with carbon fiber material; infiltrating the carbon fiber material with a thermoset resin; curing the resin to render the carbon fiber material rigid and produce a green body; removing the mandrel to produce a free-standing body; treating the free standing body with graphite to fill voids and render the green body gas tight and infiltrating the green body with molten silicon to form a silicon and silicon carbide ceramic tube.

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Clarence Center, NY, United States of America

Michael P Dunn