Abstract: A method of nitriding a refractory-nitride forming metal or metalloid articles and composite articles. A consolidated metal or metalloid article or composite is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article or composite is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article or composite is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid or composite to an article or composite of refractory nitride. In addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Abstract: This percussion welding power supply supplies welding energy through an arc between two work pieces that are forced together during or immediately following arcing. The power supply comprises a welding transformer having a primary winding and a secondary winding. Across the secondary winding, welding electrodes are connected for supplying welding current between the secondary winding and the pair of work pieces to be welded together. The power supply further comprises a capacitor bank having a pair of output terminals and means comprising electronic switching means in series with the primary winding and the output terminals for selectively connecting the output terminals across the primary winding. Control means is provided for rendering the switching means conductive, thereby causing the capacitor bank to discharge through the switching means and the primary winding to effect a welding operation.