| 摘要 |
<p>A potassium fluoro-borate glass, including silica and optionally alumina, containing at least 20 mole % potassium computed as K2(O,F2), and wherein there are more fluorine atoms in the glass than oxygen atoms. The range of compositions includes low refractive index glasses, some with refractive indices less than that of silica, and high coefficient of thermal expansion glasses, some with coefficients matching those of aluminum, copper and brass.</p> |
