Export file:


  • RIS(for EndNote,Reference Manager,ProCite)
  • BibTex
  • Text


  • Citation Only
  • Citation and Abstract

Crack populations in metals

Department of Metallurgy and Materials, University of Birmingham, UK

Special Issues: Interaction of Multiple Cracks in Materials -Volume 1

Most of our engineering metals are formed in the liquid state, but suffer mixing with air during pouring into molds. The result is the creation of doubled-over oxide films from the surface of the liquid, entrained in suspension in the metal, which, as a result of the lack of bonding between the opposed faces of the films, act as cracks. Multiple and additive populations of cracks are introduced during the processing of many metals, ensuring a high density of defects which survive in the solidified metal, and further survive plastic working by forging or rolling, etc. Many of our current engineering metals are therefore seriously impaired. This traditional impairment by these defects, called bifilms, is currently accepted as the norm. However, entrainment of the surface oxides during processing is not necessary, and its avoidance can deliver substantially defect-free metals for the first time. Improved casting technology to deliver these improvements is being successfully adopted for light alloys and steels.
  Article Metrics

Keywords metal crack; bifilm; casting; defect population; consolidation

Citation: John Campbell. Crack populations in metals. AIMS Materials Science, 2016, 3(4): 1436-1442. doi: 10.3934/matersci.2016.4.1436


  • 1. Campbell J (2015) The consolidation of metals: the origin of bifilms. J Mater Sci 51: 96–106.    
  • 2. Campbell J (2011) The origin of Griffith cracks. Metall Mater Trans B 42B: 1091–1097.
  • 3. Griffith AA (1920) The phenomenon of rupture and flow in solids. Phil Trans Roy Soc A 221: 163–198.
  • 4. Barenblatt GI (1959) The formation of equilibrium cracks during brittle fracture. PMM 23: 434–444.
  • 5. Willis JR (1967) A comparison of the fracture criteria of Griffith and Barenblatt. J Mech Phys Solids 15: 151–162.    
  • 6. Campbell J (2015) Complete Casting Handbook 2nd Edition, Elsevier, Oxford, UK.
  • 7. Raiszadeh R, Griffiths WD (2008) Duration of the atmosphere in a bifilm. Metall Mater Trans B 39B: 298–303.
  • 8. Boivert M, Christoperson D, L’Esperance G (2016) Observation of nanometric silicon oxide bifilms in a water-atomized hypereutectic cast iron powder. Metall Mater Trans B 47B: 2971–2978.
  • 9. Wang KG, Glicksman ME (2015) Phase coarsening in thin films. JOM 67: 1905–1912.    
  • 10. Xu J, Huang F, Wang X (2016) Formation mechanism of CaS-Al2O3 inclusions in low sulfur Al-killed steel after calcium treatment. Metall Matem Trans B 47B: 1217–1227.
  • 11. Campbell J (2016) Melting, remelting and casting for clean steel. Steel Res Int 87: 1–13.    
  • 12. Frost S (2015) Nuclear flaws raise safety questions in two Belgian reactors. Mater World (The Institute of Materials, Minerals and Mining, London, UK) 23: 16.
  • 13. Campbell J (2012) Stop pouring, start casting. Int J Metalcast 6: 7–18.
  • 14. Campbell J (2015) Quality Castings—A personal account of the development of the cosworth casting process. American Foundry Soc., Schaumburg, IL, USA. Originally published 2013 by Aspect Design, Malvern, UK.


This article has been cited by

  • 1. Jan Jezierski, Rafał Dojka, Krzysztof Janerka, Optimizing the Gating System for Steel Castings, Metals, 2018, 8, 4, 266, 10.3390/met8040266
  • 2. R. Dojka, J. Jezierski, J. Campbell, Optimized Gating System for Steel Castings, Journal of Materials Engineering and Performance, 2018, 10.1007/s11665-018-3497-1
  • 3. Rafał Dojka, Jan Jezierski, Niels Skat Tiedje, Geometric Form of Gating System Elements and Its Influence on the Initial Filling Phase, Journal of Materials Engineering and Performance, 2019, 10.1007/s11665-019-03973-9
  • 4. R. Taghiabadi, A. H. Shevidi, A. Razaghian, P. Abedinzadeh, Effect of Oxide Bifilms on the Fracture Behavior of AM60B Mg Alloy, Transactions of the Indian Institute of Metals, 2019, 10.1007/s12666-019-01841-7

Reader Comments

your name: *   your email: *  

Copyright Info: 2016, John Campbell, licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution Licese (http://creativecommons.org/licenses/by/4.0)

Download full text in PDF

Export Citation

Copyright © AIMS Press All Rights Reserved