Manufacture of Infrared Optics in Brittle Materials

1 online resource (138 pages) : PDF

2015

University of North Carolina at Charlotte

Infrared optics are manufactured for many different applications including: thermal imaging, surveillance, night vision, medical, laser machining, laser surgery, etc. Most infrared transparent materials are hard, brittle, or both. Unless special conditions are generated, diamond machining will lead to surfaces dominated by brittle fracture. The overall purpose of this dissertation is to further the state-of-the-art of infrared optics manufacturing. The first piece of this dissertation is to explore the ductile-brittle behavior of two different infrared materials: germanium and IRG 26 (a chalcogenide glass by Schott). These two materials are very useful IR materials: germanium for its high index of refraction and IRG 26 for its low glass transition temperature allowing for easy molding. The cutting mechanics for these materials was experimentally observed during a series of different cutting operations: face turning, planing/ruling, orthogonal turning, and ball milling. Cutting and thrust forces were measured and analyzed for the force coefficients as a function of the cutting parameters. The cutting force coefficients were found to have a significant drop as the cutting mechanics became increasingly brittle with higher chip thicknesses. The reduced cutting forces at more aggressive parameters could lead to a means of rapid prototyping of IR optics. The second piece of this dissertation is to outline a procedure developed to correct tool errors of a diamond ball mill. Two dominate tool shape errors of a ball mill are diamond position and cutting edge irregularity. An artifact based procedure was used to imprint the tool errors on a measureable part.

doctoral dissertations

Mechanical engineering

Ph.D.

Brittle Materials
Diamond Milling
Diamond Turning
Force Prediction
Freeform
Infrared Optics

Mechanical Engineering

Davies, Matthew

Evans, Christopher
Suleski, Thomas
Schmitz, Tony
Davies, Angela

Thesis (Ph.D.)--University of North Carolina at Charlotte, 2015.

This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). For additional information, see http://rightsstatements.org/page/InC/1.0/.

Copyright is held by the author unless otherwise indicated.

Owen_uncc_0694D_10773

http://hdl.handle.net/20.500.13093/etd:1337