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Title: Nanoplastic removal function and the mechanical nature of colloidal silica slurry polishing

Abstract

The nanomechanical deformations on a broad range of optical material surfaces (single crystals of Al 2O 3 [sapphire], SiC, Y 3Al 5O 12 [YAG], CaF 2, and LiB 3O 5 [LBO]; a SiO 2–Al 2O 3–P 2O 5–Li 2O glass-ceramics [Zerodur]; and glasses of SiO 2:TiO 2 [ULE], SiO 2 [fused silica], and P 2O 5–Al 2O 3–K 2O–BaO [Phosphate]) near the elastic-plastic load boundary have been measured by nanoindentation and nanoscratching to mimic the nanoplastic removal caused by a single slurry particle during polishing. Nanoindenation in air was performed to determine the workpiece hardness at various loads using a commercial nanoindenter with a Berkovich tip. Similarly, an atomic force microscope (AFM) with a stiff diamond coated tip (150 nm radius) was used to produce nanoplastic scratches in air and aqueous environments over a range of applied loads (~20-170 μN). The resulting nanoplastic deformation of the nanoscratches were used to calculate the removal function (i.e., depth per pass) which ranged from 0.18 to 3.6 nm per pass for these materials. A linear correlation between the nanoplastic removal function and the polishing rate (using a fixed polishing process with colloidal silica slurry on a polyurethane pad) of these materials was observedmore » implying that: (a) the polishing mechanism using colloidal silica slurry can be dominated by mechanical rather than chemical interactions; and (b) the nanoplastic removal function, as opposed to interface particle interactions, is the controlling factor for the polishing material removal rate. Furthermore, this correlation is consistent with the Ensemble Hertzian Multi-Gap (EHMG) microscopic material removal rate model described previously. The nanoplastic removal depth was also found to correlate to the measured nanoindentation hardness (H1) of the optical material, scaling as H 1 -3.5. Two-dimensional (2D) finite element analysis simulations of nanoindentation showed a similar nonlinear dependence of plastic deformation with the workpiece material hardness. The findings of this study are used to determine an effective Preston coefficient for the material removal rate expression and enhance the predictive nature of the nanoplastic polishing rate for various materials utilizing their material properties.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1];  [1];  [1];  [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1548339
Alternate Identifier(s):
OSTI ID: 1506708
Report Number(s):
LLNL-JRNL-748089
Journal ID: ISSN 0002-7820; 932856
Grant/Contract Number:  
AC52-07NA27344; DE‐AC52‐07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Journal of the American Ceramic Society
Additional Journal Information:
Journal Volume: 102; Journal Issue: 6; Journal ID: ISSN 0002-7820
Publisher:
American Ceramic Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 47 OTHER INSTRUMENTATION; atomic force microscopy; grinding; hardness; indentation; polishing

Citation Formats

Shen, Nan, Feigenbaum, Eyal, Suratwala, Tayyab, Steele, William, Wong, Lana, Feit, Michael D., and Miller, Phil E. Nanoplastic removal function and the mechanical nature of colloidal silica slurry polishing. United States: N. p., 2018. Web. doi:10.1111/jace.16161.
Shen, Nan, Feigenbaum, Eyal, Suratwala, Tayyab, Steele, William, Wong, Lana, Feit, Michael D., & Miller, Phil E. Nanoplastic removal function and the mechanical nature of colloidal silica slurry polishing. United States. doi:10.1111/jace.16161.
Shen, Nan, Feigenbaum, Eyal, Suratwala, Tayyab, Steele, William, Wong, Lana, Feit, Michael D., and Miller, Phil E. Thu . "Nanoplastic removal function and the mechanical nature of colloidal silica slurry polishing". United States. doi:10.1111/jace.16161.
@article{osti_1548339,
title = {Nanoplastic removal function and the mechanical nature of colloidal silica slurry polishing},
author = {Shen, Nan and Feigenbaum, Eyal and Suratwala, Tayyab and Steele, William and Wong, Lana and Feit, Michael D. and Miller, Phil E.},
abstractNote = {The nanomechanical deformations on a broad range of optical material surfaces (single crystals of Al2O3 [sapphire], SiC, Y3Al5O12 [YAG], CaF2, and LiB3O5 [LBO]; a SiO2–Al2O3–P2O5–Li2O glass-ceramics [Zerodur]; and glasses of SiO2:TiO2 [ULE], SiO2 [fused silica], and P2O5–Al2O3–K2O–BaO [Phosphate]) near the elastic-plastic load boundary have been measured by nanoindentation and nanoscratching to mimic the nanoplastic removal caused by a single slurry particle during polishing. Nanoindenation in air was performed to determine the workpiece hardness at various loads using a commercial nanoindenter with a Berkovich tip. Similarly, an atomic force microscope (AFM) with a stiff diamond coated tip (150 nm radius) was used to produce nanoplastic scratches in air and aqueous environments over a range of applied loads (~20-170 μN). The resulting nanoplastic deformation of the nanoscratches were used to calculate the removal function (i.e., depth per pass) which ranged from 0.18 to 3.6 nm per pass for these materials. A linear correlation between the nanoplastic removal function and the polishing rate (using a fixed polishing process with colloidal silica slurry on a polyurethane pad) of these materials was observed implying that: (a) the polishing mechanism using colloidal silica slurry can be dominated by mechanical rather than chemical interactions; and (b) the nanoplastic removal function, as opposed to interface particle interactions, is the controlling factor for the polishing material removal rate. Furthermore, this correlation is consistent with the Ensemble Hertzian Multi-Gap (EHMG) microscopic material removal rate model described previously. The nanoplastic removal depth was also found to correlate to the measured nanoindentation hardness (H1) of the optical material, scaling as H1-3.5. Two-dimensional (2D) finite element analysis simulations of nanoindentation showed a similar nonlinear dependence of plastic deformation with the workpiece material hardness. The findings of this study are used to determine an effective Preston coefficient for the material removal rate expression and enhance the predictive nature of the nanoplastic polishing rate for various materials utilizing their material properties.},
doi = {10.1111/jace.16161},
journal = {Journal of the American Ceramic Society},
number = 6,
volume = 102,
place = {United States},
year = {2018},
month = {11}
}

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Works referenced in this record:

An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments
journal, June 1992

  • Oliver, W. C.; Pharr, G. M.
  • Journal of Materials Research, Vol. 7, Issue 06, p. 1564-1583
  • DOI: 10.1557/JMR.1992.1564