Page 30 - PCMI Journal December 2020

Manufacturing Bespoke Aesthetic and Functional Surfaces via Photochemical Machining, Electrolytic Photoetching and Electrolytic Photopolishing Presented by: David M. Allen, Emeritus Professor of Microengineering, Cranfield University, UK
Table 2. PCM parameters for producing specific surface textures.
Metal
Application
Etchant
Surface texture features
Heat hardened steel
Abrasive plate
Ferric chloride
Sharp-edged asperities in a circular pattern
Stainless steel
Pedicure disc
Ferric chloride
Random asperities and cutting edges
AISI 01 ground flat stock steel
Bearings
10% nitric acid
Chevrons, dimples and grooves
AISI 52100 steel, 920HV
Bearings resulting in a coefficient of friction reduced by 30%.
5wt% ferric chloride, 20wt% hydrochloric acid and water
Bio-inspired “snakeskin” : circular and elliptical pillars
Acknowledgements
DMA wishes to thank Glenn and Sean Dooley (Northwest Etch, Tacoma, WA, USA), Phil
Greiner (PEI, Milford, MA, USA), Lee Weston (Precision Micro Ltd., Birmingham, UK) and Dr Glenn Leighton (Cranfield University, Bedford, UK) for their contributions to this paper and discussions on the various manufacturing techniques used in part production.
References
1. DM Allen, Photochemical Machining and Photoelectroforming, ISBN 978-1-5262-0188-1,
3rd reprint 2019, (a) p.66, (b) p.27.
2. DM Allen, AJ Hegarty and DF Horne, Surface textures of annealed AISI 304 stainless steel
etched by aqueous ferric chloride - hydrochloric acid solutions, Transactions Institute of
Metal Finishing, 59, 25-9 (1981)
3. DM Allen, DF Horne and GWW Stevens, Production of high resolution photoetched
stainless steel plaques, J. Phot. Sci., 28, 43-7 (1980)
4. A Visser and D Weissinger, Spray Etching of Stainless Steel, PCMI Publication #4000 (1993),
(a) p.8, (b) pp.13-14.
5. A Abel, The desirable characteristics of photoetch quality stainless steels and their
potential market, MSc thesis, Cranfield University MSc thesis (2002)
6. P Greiner, private correspondence (2020)
7. DM Allen, JRC Brightman, PJ Gillbanks and PM Smith, Three-dimensional photochemical
machining, CIRP Annals, 36/1, 91-4 (1987)
8. DM Allen, TN Talib and DF Horne, Surface textures and process characteristics of the
electrolytic photoetching of annealed AISI 304 stainless steel in hydrochloric acid,
Precision Engineering, 5, 51-6 (1983)
9. DM Allen and TN Talib, Manufacture of stainless steel edge filters: an application of
electrolytic photopolishing, Precision Engineering, 5, 57-9 (1983)
10. T Baldhoff, V Nock and AT Marshall, Through-Mask Electrochemical Micromachining of
Aluminum in Phosphoric Acid, Journal of The Electrochemical Society, 164 (9) E194-E202
(2017)
11. John J Frantzen, US Patent 4,240,806, Abrading Material, Dec 23, 1980
Issue 136 December 2020 PCMI Journal 30