| 摘要 |
An article of high strength glass for use within a range of temperatures comprises an inner glass and an outer glass fused together. In the said range, the outer glass has a lower viscosity than the inner glass, and the outer glass is in a plastic state and the inner glass in a solid state. The inner glass may be enclosed within two surface layers of outer glass; there may be an intermediate region of composition gradually varying from that of the outer glass to that of the inner glass. The article may be made by applying to an inner glass sheet two outer glass sheets and heating to fuse the outer sheets to the inner sheets; or an inner glass article may be dipped into molten outer glass. Exemplified are (1) borosilicate glass rods coated with lead glass, and (2) As/S glass rods coated with As/S glass having a composition of different proportions. |
