| 摘要 |
A glass article which has a surface of optical quality is obtained by moulding a hydrated glass, avoiding grinding and polishing operations. The starting material is an anhydrous glass containing, on molar basis 72-82 % of SiO2, 10-17 % of Na2O and/or K2O and 5-15 % of ZnO and/or PbO, this glass is hydrated to a water content of 0.5 to 10 % by weight and is then moulded against a matrix whose moulding surface itself is of optical quality. The moulding is performed at a pressure of 275 to 1400 bars and at a temperature of 250 to 500 DEG C, at which the hydrated glass is sufficiently fluid. The glass article thus obtained may be a lens, a mirror or a grating.
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