| 摘要 |
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.
|
