GLASS IMMUNE TO FUMES OF ALKALI METALS

Abstract : The glass consists of the following percents by weight: SiO2 12 plus or minus 2, B2O3 32 plus or minus 2, Al2O3 32.5 plus or minus 2, CaO 20 plus or minus 1.5, SrO 3.5 plus or minus 1.5 and contain not more than 0.03% Fe2O3. The glass does not crystallize during founding and working, it can be worked out well in the flame of a torch, articles with a wall thickness of 0.2-0.4 mm can be made of it, and it can be vacuum soldered to Kovar and molybdenum.