Experiments and observations regarding the mechanisms of glass removal in magnetorheological finishing

Abstract

Recent advances in the study of the magnetorheological finishing (MRF) have allowed for the characterization of the dynamic yield stress of the magnetorheological (MR) fluid, as well as the nanohardness (H _nano) of the carbonyl iron (CI) used in MRF. Knowledge of these properties has allowed for a more complete study of the mechanisms of material removal in MRF. Material removal experiments show that the nanohardness of CI is important in MRF with nonaqueous MR fluids with no nonmagnetic abrasives, but is relatively unimportant in aqueous MR fluids or when nonmagnetic abrasives are present. The hydrated layer created by the chemical effects of water is shown to change the way material is removed by hard CI as the MR fluid transitions from a nonaqueous MR fluid to an aqueous MR fluid. Drag force measurements and atomic force microscope scans demonstrate that, when added to a MR fluid, nonmagnetic abrasives (cerium oxide, aluminum oxide, and diamond) are driven toward the workpiece surface because of the gradient in the magnetic field and hence become responsible for material removal. Removal rates increase with the addition of these polishing abrasives. The relative increase depends on the amount and type of abrasive used.

© 2001 Optical Society of America

Removal rate model for magnetorheological finishing of glass

Jessica E. DeGroote, Anne E. Marino, John P. Wilson, Amy L. Bishop, John C. Lambropoulos, and Stephen D. Jacobs
Appl. Opt. 46(32) 7927-7941 (2007)

Shear stress in magnetorheological finishing for glasses

Chunlin Miao, Shai N. Shafrir, John C. Lambropoulos, Joni Mici, and Stephen D. Jacobs
Appl. Opt. 48(13) 2585-2594 (2009)

Nanoindentation hardness of particles used in magnetorheological finishing (MRF)

Aric B. Shorey, Kevin M. Kwong, Kerry M. Johnson, and Stephen D. Jacobs
Appl. Opt. 39(28) 5194-5204 (2000)

Process parameter effects on material removal in magnetorheological finishing of borosilicate glass

Chunlin Miao, John C. Lambropoulos, and Stephen D. Jacobs
Appl. Opt. 49(10) 1951-1963 (2010)

Zirconia-coated carbonyl-iron-particle-based magnetorheological fluid for polishing optical glasses and ceramics

Shai N. Shafrir, Henry J. Romanofsky, Michael Skarlinski, Mimi Wang, Chunlin Miao, Sivan Salzman, Taylor Chartier, Joni Mici, John C. Lambropoulos, Rui Shen, Hong Yang, and Stephen D. Jacobs
Appl. Opt. 48(35) 6797-6810 (2009)