Ronald H Chand

US Patent:

20070207268, Sep 6, 2007

Filed:

Oct 12, 2005

Appl. No.:

11/249860

Inventors:

R. Webb - Escondido CA, US
Ronald Chand - Paxton MA, US
Clifford Tanaka - Lihue HI, US
Colby Foss - Kapaa HI, US

International Classification:

C23C 16/26
C23C 16/00

US Classification:

427249600, 427248100

Abstract:

A process for making a ribbed light weight composite mirror unit. Preferred embodiments are silicon carbide composite structures. Preferred structures comprise a front smooth silicon carbide surface supported by a silicon carbide ribbed back support. The ribbed back support may be produce by milling out portions of SiC block or by the joining of multiple simple shapes to form the ribbed support. At least the smooth front SiC surface is produced using a chemical vapor composite process as described in the Background Section. These include very large mirrors that resist gravitational sagging and smaller scanning and stepping mirrors that can be pointed quickly and accurately with minimal hysteresis. Preferred milling techniques include precision water jet milling. Special bonding techniques are described to produce ribbed support from multiple parts.

US Patent:

20140326403, Nov 6, 2014

Filed:

May 5, 2014

Appl. No.:

14/269621

Inventors:

- Amherst NH, US
Ronald H. Chand - Paxton MA, US
Stephen G. DiPietro - Mont Vernon NH, US
Vimal K. Pujari - Northborough MA, US

International Classification:

C04B 41/00
C04B 35/571

US Classification:

156281, 1563082, 156285

Abstract:

Method and system for bonding two or more CVD SiC articles together without the use of interface materials using applied forces from about 0.0035 MPa to about 0.035 MPa. The articles are pretreated for bonding. Graphite or other fixtures are used to apply forces in a vacuum or inert gas environment. Temperatures from about 1900 C. to about 2200 C. are used to initiate a β→α transition in the SiC to create bonded CVS SiC articles.