| 摘要 |
In the present invention, there is disclosed a method of making metal electrode on spark plug ceramic insulator by method of laser building up surface. An electrode (3) in the form of a ring about a central electrode (2) is applied to the insulator (1) material, wherein a diffusion layer between the insulator (1) material and the electrode (3) excess material is created, First, in order to prevent occurrence of thermal stresses, the spark plug ceramic insulator (1) is preheated by resistance heating to a temperature in the range of 500 to 700 degC at a rate in the range of 100 to 150 degC/min. Subsequently, it is subjected to rotation at a rate depending on a required thickness of the wire weld bead, wherein the end section of the insulator (1) is preheated at a distance 12 to 15 mm from the edge thereof by the action of a laser beam swept homogeneously to a rectangular surface at a power density of the lased preheating in the range of 3500 to 4000 W/cme2 to a wire welding temperature set below insulator (1) material phase transformation temperature. After the wire welding temperature is achieved, the feed of the wire in the region of the electrode formation is activated at a feeding rate in the range of 0.5 up to 3 mm/360 degrees, and along with the activation of the wire feed the laser power reduces to a power density in the range of 700 to 900 W/cme2, whereby all over the surface building period, there is simultaneously heated the end section of the insulator (1) at a distance in the range of 12 to 15 mm from the edge thereof. After welding-on a cover of 360 degrees + 30 degrees of the insulator (1), the wire feed is deactivated and the laser power is reduced to zero. |
