| 摘要 |
<p>A mass of slag or other nonconducting material with vacuous cells or pores separated by thin walls is used for heat insulation. A volatile metal such as zinc or cadmium in the powdered state is introduced into a molten mass of the material, and the mixture is exposed to reduced pressure to vaporize the metal and form the cells. The mass is then cooled, and the metal is condensed and deposited on the walls of the cells; a casing is provided to resist external strain. Gas-filled cells may also be formed within the mass.</p> |
