摘要 |
A mirror having optical quality reflective faces is prepared by pressing of metallurgical powders. An optical quality surface, free of scratches and irregularities, is formed by pressing the faces with an optical quality tool face, applied to the face at an acute angle to achieve a degree of metal flow. The mirror is progressively formed, by first pressing an assembly of powder to a "green" powder mirror, sintering the pressed powder, and then repressing the sintered mirror using a tool having optical quality surfaces on the faces contacting the mirror faces. The mirror is annealed, repressed with the tool having optical quality surfaces, and coated on the reflective surfaces with a thin metallic coating. This technique is particularly effective for preparing large numbers of mirrors with multiple facets requiring precise facet intersections, as the pressing tool can be adjusted to produce highly exact facet intersections which are then reproduced exactly in subsequent mirrors.
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