Claims
- 1. A process for figuring the surface of a metal mirror to a predetermined curvature, comprising:
- a. sensing the configuration of the mirror surface to locate areas of the mirror surface which are higher than desired,
- b. directing a stream of phosphoric acid into contact with said areas of the mirror surface which are higher than desired, said phosphoric acid being diluted with a mixture of 30 to 60 weight percent water and 70 to 40 weight percent ethylene glycol, and
- c. passing a current of 10 to 200 milliamps through the stream to said higher area to electro-chemically polish said area.
- 2. The process of claim 1 wherein the mirror is rotated and the stream is passed through a tube, said tube being traversed along a radius of the mirror as the mirror is being rotated.
- 3. The process of claim 2 wherein the current is applied only when the stream is being directed onto said higher areas.
- 4. The process of claim 3 wherein the flow rate of the fluid is 1/4 to 2 gallons per minute.
- 5. The process of claim 4 wherein the end of the tube is 1/4 to 1 inch from the mirror surface and the current is applied to the mirror under a voltage of 5 to 20 volts DC.
- 6. A process for figuring of a beryllium mirror to a predetermined curvature, comprising;
- a. sensing the configuration of the mirror surface to locate areas of said mirror surface which are higher than desired,
- b. directing a stream of diluted phosphoric acid into contact with said areas of the mirror's surface which are higher than desired, said phosphoric acid being diluted with 97 to 94 weight percent of a mixture of 30 to 60 weight percent water and 70 to 40 weight ethylene glycol, and
- c. passing a current of 10 to 200 milliamps through the steam to said higher area to electrochemically polish said area.
- 7. The process of claim 6 wherein the current is a direct current of about 25 to 100 milliamps.
- 8. The process of claim 7 wherein the mirror is simultaneously rotated at a speed of 6 to 20 revolutions per minute and the stream of diluted phosphoric acid is traversed along the radius of the mirror at a rate of 0.5 to 2.0 inches per minute.
DEDICATORY CLAUSE
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalties thereon.
US Referenced Citations (5)