A method of forming a metal electrode on the ceramic insulator of a spark plug

The method of creating a metal electrode on the ceramic insulator of a spark plug with a deposit of additional material using the laser weld deposition method, where this metal electrode, formed by a diffusion metallic layer of the joint between the weld deposit of the smelted wire and the insulator, is in the shape of a ring in the end part of the insulator body around the central electrode of the spark plug, wherein first, the spark plug insulator is preheated by resistance heating to the temperature of 500 to 700° C. at the rate of 100 to 150° C./min to prevent the creation of thermal stresses, and subsequently it is exposed to rotation at the speed depending on the required wire weld deposit thickness, where the end part of the insulator, at the distance of 12 to 15 mm from its margin, is preheated to the temperature of the wire weld deposition determined below the temperature of phase transformation of the insulator material by the action of a laser beam swept into a rectangular area homogenously at the power density of laser preheating within the range of 3,500 to 4,000 W/sq. cm, after achieving the weld depositing temperature of the wire, the wire feeding into the area of the created electrode is activated, with a feed speed from 0.5 to 3 mm/360°, and together with the wire feeding activation, the laser output decreases to the power density of 700 to 900 W/sq. cm, while throughout the weld deposition, the end part of the insulator is simultaneously heated at a distance of 12 to 15 mm from its margin and after weld depositing an overlap of 360 °+30° of the insulator, the wire feeding is deactivated and the laser output is decreased to zero.