Characterization of optical surface grinding using bound and loose abrasives

2011 2011

Other formats: Order a copy

Abstract (summary)

Large optical systems fabrication is a demanding task due to the tight requirements and big scales. To make mirrors up to 8.4m in diameter necessitates technological development in materials, tooling, and metrology. These advancements are designed to not only produce optics on a near-unheard of scale, but to improve fabrication methods with each piece. For an optical surface to be properly polished, the amount of material removed during polishing must be greater than the volume of damage left behind by the grinding process. Mixed-mode grinding, which combines bound abrasives with a compliant binder material, is a valuable tool at this stage as it creates less damage while maintaining a fast and uniform cutting rate than traditional loose abrasive grinding.

These materials are challenging for large optical surfaces due to the honeycomb structures used to lightweight the mirrors. Development is done to adapt the abrasive to handle the very low pressures and speeds required to avoid imprinting structure on the optical surface.

We take a comprehensive approach in measuring mixed-mode behavior using 3M Trizactâ„¢. Prior works on bound abrasives have focused on specific properties: removal rates, subsurface damage, etc. None have yet to look at the entire scope of the material and its benefits. These properties will be analyzed along with different behaviors regarding surface scattering, Twyman effect bending moments, glazing, manufacturing expenses, and failure mechanisms. This comprehensive understanding of the abrasive allows manufacturers to create better grinding schedules and reduce overall expenses in fabrication. Trizact shows up to a three times faster removal rate while producing 30% less subsurface damage than loose abrasives of similar size. Additionally, the surface has scatters less light which can be adapted through changes in processing to create a specular reflection for optical surface metrology.

Based on our findings, this type of abrasive integrates into current optical fabrication processes as a pre-polishing material. Here, the transition to these abrasives becomes cost effective by rapidly eliminating damage created during the generating of the surface and reducing the amount of polishing required.

Indexing (details)

0752: Optics
Identifier / keyword
Pure sciences; Bound and loose abrasives; Grinding; Optical fabrication; Subsurface damage; Twyman effect
Characterization of optical surface grinding using bound and loose abrasives
Johnson, James Ballard, II
Number of pages
Publication year
Degree date
School code
DAI-B 73/04, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
Burge, James H.
Committee member
Parks, Robert E.; Sasian, Jose M.
The University of Arizona
Optical Sciences
University location
United States -- Arizona
Source type
Dissertations & Theses
Document type
Dissertation/thesis number
ProQuest document ID
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.