COMPOSITE MEMBER OF BERYLLIUM THIN PLATE AND COPPER MEMBER AND METHOD FOR JOINING THEM

摘要

PURPOSE:To provide a composite member of a beryllium thin plate and a copper member whose connection strength and gastightness are high and a method for joining the beryllium thin plate and the copper member. CONSTITUTION:A retainer 11 of an X-ray bulb 1 is formed out of oxygen free copper and an X-ray transmission window 12 is made of beryllium. A joint face of the retainer 11 and the X-ray transmission window 12 is electrically plated in multilayer in order of a chromium layer 13 and a nickel layer 14 thereon. The retainer 11 and the X-ray transmission window 12 are joined with a wax material 15. When the wax material 15 is heated and the retainer 11 and the X-ray transmission window 12 are joined together, beryllium which is diffused from the X-ray transmission window 12 to the nickel layer 14 is hardly diffused to the chromium layer 13 because the retainer 11 is coated with the chromium layer 13 whose affinity with beryllium is low. Thereby, since the erosion of the X-ray transmission window 12 is prevented, the good joint of the retainer 11 and the X-ray transmission window 12 is formed.