MRF Applications [electronic resource] : Measurement of Process-dependent Subsurface Damage in Optical Materials using the MRF Wedge Technique

Published:: Washington, D.C. : United States. Dept. of Energy, 2005.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description:: PDF-file: 11 pages; size: 1.1 Mbytes
Additional Creators:: Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information

Access Online

www.osti.gov

Availability

Finding items...

Restrictions on Access:

Free-to-read Unrestricted online access

Summary:

Understanding the behavior of fractures and subsurface damage in the processes used during optic fabrication plays a key role in determining the final quality of the optical surface finish. During the early stages of surface preparation, brittle grinding processes induce fractures at or near an optical surface whose range can extend from depths of a few mm to hundreds of mm depending upon the process and tooling being employed. Controlling the occurrence, structure, and propagation of these sites during subsequent grinding and polishing operations is highly desirable if one wishes to obtain high-quality surfaces that are free of such artifacts. Over the past year, our team has made significant strides in developing a diagnostic technique that combines magnetorheological finishing (MRF) and scanning optical microscopy to measure and characterize subsurface damage in optical materials. The technique takes advantage of the unique nature of MRF to polish a prescribed large-area wedge into the optical surface without propagating existing damage or introducing new damage. The polished wedge is then analyzed to quantify subsurface damage as a function of depth from the original surface. Large-area measurement using scanning optical microscopy provides for improved accuracy and reliability over methods such as the COM ball-dimple technique. Examples of the technique's use will be presented that illustrate the behavior of subsurface damage in fused silica that arises during a variety of intermediate optical fabrication process steps.

Report Numbers:

E 1.99:ucrl-proc-217271
ucrl-proc-217271

Subject(s):

Engineering

Other Subject(s):

Note:

Published through SciTech Connect.
11/02/2005.
"ucrl-proc-217271"
Presented at: Boulder Damage Symposium, Boulder, CO, United States, Sep 19 - Sep 21, 2005.
Miller, P E; Wong, L L; Davis, P J; Steele, W A; Suratwala, T I; Menapace, J A.

Funding Information:

W-7405-ENG-48

View MARC record | catkey: 14105008