Next Article in Journal
Generating, Separating and Polarizing Terahertz Vortex Beams via Liquid Crystals with Gradient-Rotation Directors
Previous Article in Journal
Optical Characterization of AlAsSb Digital Alloy and Random Alloy on GaSb
Article Menu
Issue 10 (October) cover image

Export Article

Open AccessArticle
Crystals 2017, 7(10), 315; doi:10.3390/cryst7100315

Crystal Engineering for Mechanical Strength at Nano-Scale Dimensions

Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
Academic Editor: Shujun Zhang
Received: 22 September 2017 / Revised: 14 October 2017 / Accepted: 15 October 2017 / Published: 18 October 2017
(This article belongs to the Section Crystal Engineering)
View Full-Text   |   Download PDF [1542 KB, uploaded 18 October 2017]   |  

Abstract

The mechanical strengths of nano-scale individual crystal or nanopolycrystalline metals, and other dimensionally-related materials are increased by an order of magnitude or more as compared to those values measured at conventional crystal or polycrystal grain dimensions. An explanation for the result is attributed to the constraint provided at the surface of the crystals or, more importantly, at interfacial boundaries within or between crystals. The effect is most often described in terms either of two size dependencies: an inverse dependence on crystal size because of single dislocation behavior or, within a polycrystalline material, in terms of a reciprocal square root of grain size dependence, designated as a Hall-Petch relationship for the researchers first pointing to the effect for steel and who provided an enduring dislocation pile-up interpretation for the relationship. The current report provides an updated description of such strength properties for iron and steel materials, and describes applications of the relationship to a wider range of materials, including non-ferrous metals, nano-twinned, polyphase, and composite materials. At limiting small nm grain sizes, there is a generally minor strength reversal that is accompanied by an additional order-of-magnitude elevation of an increased strength dependence on deformation rate, thus giving an important emphasis to the strain rate sensitivity property of materials at nano-scale dimensions. View Full-Text
Keywords: crystal (grain) size; nanomaterials; mechanical strength; Hall-Petch relation; dislocation pile-ups; patented steel wire; non-ferrous materials; nano-twinned material; superalloys; composites; strain rate sensitivity crystal (grain) size; nanomaterials; mechanical strength; Hall-Petch relation; dislocation pile-ups; patented steel wire; non-ferrous materials; nano-twinned material; superalloys; composites; strain rate sensitivity
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Armstrong, R.W. Crystal Engineering for Mechanical Strength at Nano-Scale Dimensions. Crystals 2017, 7, 315.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Crystals EISSN 2073-4352 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top