| 摘要 |
An optical element is obtained by placing pure microcrystalline cadmium sulphide in a pressure mould, subjecting the material to 10,000-55,000 p.s.i. whilst maintaining its temperature at 510-800 DEG C. for such a period of time, normally 10-40 minutes, that a body being of at least 99% of the theoretical density of cadmium sulphide is formed, and thereafter releasing the pressure and cooling the mould. The process is preferably carried out in an inert atmosphere or a vacuum. A metallic mounting may be placed in the mould so that the element is formed in the mounting. The heating is preferably high-frequency heating. The product has a high refractive index and is a good transmitter of infra-red. |
