| 摘要 |
PURPOSE:To make such airtightness that is stable for hours securable by using the cermet made up of alumina powder, containing the specified quantity of a magnesium constituent as a base, for a ceramic light emitting tube end blocking material. CONSTITUTION:At the time of sintering a mixed body between metal (one type selected from Mo, Cr, Fe and Ni or more) and aluminum oxide (alumina) and thereby manufacturing a cermet sintering body, such material powder that contained a magnesium constituent as much as 500ppm-1500ppm in a base material is used. For example, aluminum powder, containing the magnesium constituent as much as 100ppm, and tungsten are mixed together, and after being pressed and desorbed, it is attached to an electrode and a lead rod, then it is baked in a vacuum. with this constitution, a very dense cermet sintering body is produced in the state that a thermal expansion characteristic and conductivity are satisfied, thus high airtight reliability is maintainable over hours.
|
