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Armstrong, Dr. Ronald W.

Armstrong, Dr. Ronald W.
Professor Emeritus of Mechanical Engineering
Department of Mechanical Engineering

Research Interests 

  • Strength and structure of materials
  • Dislocation modeling, crystallography
  • X‑ray diffraction topography
  • Single crystal/polycrystal deformation/fracturing
  • Explosive crystals
  • Dynamic plasticity
  • Fracture toughness
  • Hardness testing
  • Prosthetic devices
  • Electronic materials


  • Postdoctoral Studies, Leeds University, UK, 1959
  • Ph.D., Carnegie Mellon University, 1958
  • B.E.S., Johns Hopkins University, 1955

Honors and Awards 

  • AIME Robert Lansing Hardy Gold Medal for 1962
  • Senior Fulbright‑Hays Fellow, New Zealand, 1974
  • NATO Advanced Study Institute Lecturer, England 1979, Crete 1985
  • Who's Who in America, 1982‑89
  • Liaison Scientist, Office of Naval Research‑London, UK 1982‑1984, 1991
  • Visiting Research Fellow, now Life Member, Clare Hall, Univ. Cambridge, UK, 1984
  • Symposium in Honor of Professor Ronald W. Armstrong, Dynamic Deformation: Constitutive Modeling, Grain Size, and Other Effects, TMS 2003, 132nd Annual Meeting and Exhibition, 3/2-6/2003, San Diego, CA; see Metall. Mater. Trans. A, 35A, 2545-2745 (2004).
  • DYMAT John Rinehart Award, 2015
  • Invited to present/publish more than 50 technical papers in Symposia, among more than 300 technical journal and symposium publications.

Professional Memberships and Service 

  • Fellow - American Society for Metals
  • Life Member - Clare Hall, University of Cambridge, U.K.
  • Honorary Member - Materials Research Society of India and Indian Institute of Metals
  • Member - American Physical Society; American Society for Materials; The (TMS) Minerals, Metals and Materials Society; and, Materials Research Society.

Selected Publications 

RECENT PUBLICATIONS (among ~350 in journals, books and proceedings)      

  • R.W. Armstrong and N. Balasubramanian, Physically-Based and Power-Law Constitutive Relations for Higher Temperature Metal Processing and Creep-Type Deformations, The Minerals, Metals & Materials Society, 69, [5], 822-829 (2017).
  • R.W. Armstrong and N. Balasubramanian, Unified Hall-Petch description of nano-grain nickel hardness, flow stress and strain rate sensitivity measurements, AIP Advances, 7, [085010], 1-5 (2017).
  • R.W. Armstrong, W.L. Elban, and S.M. Walley, Crystal Indentation Hardness, Crystals, Vol. 7, No.1 (2017)
  • R.W. Armstrong, Hall-Petch description of nanopolycrystalline Cu, Ni and Al strength levels and strain rate sensitivities, Philosophical Magazine, 96, [29], 3097-3108 (2016).
  • R.W. Armstrong, Hall-Petch Relationship: Use in Characterizing Properties of Aluminum and Aluminum Alloys, Encyclopedia of Aluminum and Its Alloys (2016).
  • R.W. Armstrong, Crystal Dislocations, Crystals, 6 (1), 9 (2016).
  • R.W. Armstrong and J.G. Glenn, Electrical Role for Severe Storm Tornadogenesis (and Modification). Journal of Climatology & Weather Forecasting, Vol. 3, Issue 3 (2015).
  • (invited) R.W. Armstrong and Q.Z. Li, Dislocation mechanics of high rate deformations, Metall. Mater. Trans. A, 46A, 4438-4452 (2015).
  • R.W. Armstrong, Material grain size and crack size influences on cleavage fracturing, Phil. Trans. R. Soc. A, in theme issue ‘Fracturing across the Multi-scales of Diverse Materials’, R.W. Armstrong, S.D. Antolovich, J.R. Griffiths and J.F. Knott, co-editors, Phil Trans. R. Soc. A, 373, 20140124 (2015) 18 pp.
  • V.E. Panin and R.W. Armstrong, Hall-Petch analysis for temperature and strain rate dependent deformation of polycrystalline lead, (Russian) Physical Mesomechanics, 18, [3], 5-10 (2015).
  • (invited) R.W. Armstrong, Plasticity: Grain Size Effects III, Elsevier Materials Science and Materials Engineering (MSME) module, 12/2015 publication.
  • (invited) R.W. Armstrong,, Dislocation Pile-Ups, Material Strength Levels and Thermal Activation. Metall., Mater. Trans A, 47A, available online 10/2015.
  • (invited) R.W. Armstrong, 60 Years of Hall-Petch: Past to Present Nanoscale Connections, Symp. Strength of Fine Grained Materials – 60 years of Hall-Petch, Univ. Tokyo, 7/16-18/2013; (Japan) Materials Trans., 55, [1], 2-12 (2014).
  • (invited) R.W. Armstrong, Bertram Hopkinson’s pioneering work and the dislocation mechanics of high rate deformations and mechanically-induced detonations, Phil. Trans. Roy. Soc. A, 372, 20130181 (2014); DYMAT Hopkinson 1914-2014 Centenary Conference, Cambridge, U.K., 9/9-11/2014 .
  • (invited) R.W. Armstrong, Symmetry aspects of dislocation-effected crystal properties; material strength levels and x-ray topographic imaging, Symmetry, 6, 148-163 (2014).
  • (invited) R.W. Armstrong, Sir Alan Cottrell and the dislocation mechanics of fracturing, Cottrell Memorial Symposium, 13th Int. Conf. Fract. (ICF13), 6/16-21/2013, Beijing, CN; Int. J. Strength, Fracture and Complexity 8, 105-115 (2013/2014).
  • R.W. Armstrong, W.L. Elban, and S.M. Walley, Elastic, Plastic, Cracking Aspects of the Hardness of Materials. International Journal of Modern Physics B, Vol. 27, No. 8 (2013).

Related News 

Armstrong Receives 2015 John Rinehart Award
Mechanical Engineering Professor Emeritus Ronald Armstrong receives 2015 John Rinehart Award work in dynamic deformation. April 3, 2015

Armstrong Co-Edits New Royal Society Philosophical Transactions Themed Journal
The Royal Society publishes "Fracturing across the Multi-scales of Diverse Materials." February 13, 2015

Dr. Armstrong has joined with Dr. Stephen Walley at Cambridge and Professor Wayne Elban at Loyola University Maryland to co-edit the current MDPI Crystals journal Special Issue in progress on "Crystal Indentation Hardness"; see the website at: www.mdpi.com/journal/crystals/special_issues/cryst_indentation_hardness