abstract |
Glass for producing articles by centrifugal casting composed essentially of 60% SiO2, 18% B2O3, 7% MgO, 6% Li2O, 4% A12O3, 3% BaO, 1% CaO and 1% K2O, within tolerances of about + OR - 2 percent, all of the percentages being by weight; and article formed by helium-tight, stress-free fusion of the glass with an Fe-Ni-Co alloy. |