Process optimization for high removal rates with MRF

William Messner; Christopher Hall

doi:10.1117/12.2690855

29 November 2023 Process optimization for high removal rates with MRF

William Messner, Christopher Hall

Proceedings Volume 12778, Optifab 2023; 127780D (2023) https://doi.org/10.1117/12.2690855
Event: SPIE Optifab, 2023, Rochester, New York, United States

Abstract

Magnetorheological Finishing (MRF®) is a polishing process with a wide parameter space. Through the selection of various fluid compositions, wheel sizes, and other process settings, a large suite of possible tools is available. Most of the process space has been engineered to satisfy final figuring in which typically hundreds or possibly thousands of nanometers of removal are required. For larger aperture optics and/or higher amplitude corrections, there is interest in efficiently removing larger volumes of material. Continued optimization of the fluid delivery system, specifically the nozzle design, has resulted in dramatically improved removal rates. Initial process optimization has been performed to integrate these improvements into production. A new nozzle design produced improved removal rates of up to 200% relative to the standard nozzle designs. With the new design, several factors needed to be investigated to verify its suitability for production. Foremost among these was the performance around the edges of the polished aperture. Transitioning an MRF tool onto an optical surface typically produces a zone where the tool shape and/or rate differs from the characterized tool. The size of the zone scales with the size of the tool, and within this zone the removal is not well predicted. Varying the removal function (also referred to as the spot) size around the edges to mitigate this effect was assessed with promising results. Finally, the stability of the tool was characterized. The stability of the tool affects global unpredicted removal errors, particularly in higher spatial frequency bands. Preliminary results have shown performance at least comparable to the standard designs.

Conference Presentation

Citation Download Citation

William Messner and Christopher Hall "Process optimization for high removal rates with MRF", Proc. SPIE 12778, Optifab 2023, 127780D (29 November 2023); https://doi.org/10.1117/12.2690855

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available