Optimization of metal-ceramic pressure seal construction

Abstract

The impact of thickness of metal current leads on the rigidity of the high-voltage metal-ceramic pressure seal of the electron beam gun is determined during operation. The aim of research is to optimize the metal-ceramic pressure seal construction by means of current lead thickness variation. The movement behavior of a pressure seal node has been set during operation by means of computer simulation. The analysis of displacement fields has been carried out. It has shown that the points of maximum strains along the X axis are concentrated in the center of the Kovar free surface, and along the Y axis they increase smoothly from the pinning point and reach the maximum near the joint and ceramics. It has been established that the maximum X and Y displacement decrease more noticeable in case of the increase of current lead thickness from 0.3 to 0.8 mm. Thus, the increase of thickness from 0.3 mm to 0.5 mm leads to the decrease of displacements by 80% and 64% for Y and X respectively, in case of current lead thickness of 0.8 mm the displacements are reduced by 95% and 86 % for Y and X respectively. It is determined that 0.8 mm is the optimum thickness of the current lead. This result is based on the level of the maximum principal tensile stresses under the pressure seal brazing and minimum node displacements during operation.