Elsevier

Acta Metallurgica et Materialia

Volume 40, Issue 9, September 1992, Pages 2361-2373
Acta Metallurgica et Materialia

The analysis of internal strains measured by neutron diffraction in Al/SiC metal matrix composites

https://doi.org/10.1016/0956-7151(92)90155-8Get rights and content

Abstract

Neutron diffraction measurements of internal strain development during tensile loading are analysed so as to deduce the extent and mechanisms of load transfer taking place between matrix and reinforcement. It is demonstrated that the observed lattice strains in Al/20 vol.% SiC whisker and particulate composites can be understood largely in terms of an elastic transfer of load arising from the higher stiffness of the reinforcing phase, however at loads approaching a conventional 0.2% yield stress, plastically induced stresses also become important. Furthermore, in the particulate composite there is clear evidence that stress relaxation mechanisms are also important.

Résumé

On analyse des mesures de diffraction de neutrons relatives au développement de la déformation interne pendant une charge en traction afin d'en déduire l'étendue et le mécanisme du transfert de charge qui se produit entre la matrice et le renfort. On démontre que les déformations du réseau observées dans un composite Al/20% en vol. de poils et de particules de SiC peuvent être largement interprétées par un transfert elastique de charge qui résulte de la plus forte raideur de la phase renfort, cependant pour des charges avoisinant la contrainte classique à 0,2% de la limite èlastique, les contraintes induites plasiquement deviennent aussi importantes. De plus, dans le composite à particules, il est clair que les mecanismes de relaxation de la contrainte sont aussi importants.

Zusammenfassung

Neutronenbeugungsexperimente zur Entwicklung der Verzerrungen während der Zugbelastung werden so analysiert, daβ Ausmaβ und Mechanismus des Lasttransfers, der zwischen Matrix und Verstärkungselement abläuft, abgeleitet werden können. Es wird gezeigt, daβ die beobachteten Gitterverzerrungen in Al/20 Vol.% SiC-Whisker- und Teilchen-Verbundwerkstoffen weitgehen anhand des elastischen Transfers der Last wegen der höheren Steifigkeit der verstärkenden Phase verstanden werden können. Allerdings werden plastisch induzierte Spannungen auch wichtig, wenn die Last die konventionelle Flieβspannung bei 0,2% Dehnung erreicht. Desweiteren gibt es klare Hinweise, daβ der Spannungsrelaxationsmechanismus in dem Verbund mit Teilchen auch wichtig ist.

References (17)

  • P.J. Withers et al.

    Acta metall.

    (1989)
  • L.M. Brown et al.

    Acta metall.

    (1975)
  • O.B. Pedersen

    Acta metall.

    (1983)
  • T. Mori et al.

    Acta metall.

    (1980)
  • A.J. Allen et al.

    Adv. Phys.

    (1985)
  • A.J. Allen et al.

    Res. Stresses Sci. Tech.

    (1987)
  • P.J. Withers
  • J.D. Eshelby
There are more references available in the full text version of this article.

Cited by (115)

  • Effect of nanoparticles on creep behaviour of metals: A review

    2023, Journal of Materials Research and Technology
  • Review on study of internal load transfer in metal matrix composites using diffraction techniques

    2022, Materials Science and Engineering: A
    Citation Excerpt :

    These signify that at applied compressive stresses higher than these points the load-bearing capability of the ceramic phase in individual composite samples reduces. Following the discussions in section 2 and the work of Allen et al. [27], these points correspond to the initiation of damage in the ceramic phase. As the load-bearing capacity of the ceramic is exhausted, the load is transferred back to the metallic phase.

  • VHCF damage in duplex stainless steel revealed by microbeam energy-dispersive X-ray Laue diffraction

    2021, International Journal of Fatigue
    Citation Excerpt :

    Traditionally, experimental studies of mechanical properties of metals and alloys are dominated by surface probe techniques such as optical and scanning electron microscopy (SEM) [9–12] where dislocation arrangements can hardly be observed unless special techniques such as the use of electron channeling contrast are applied. As an alternative, X-ray and neutron diffraction techniques are nondestructive, surface- and bulking-probing approaches to study fatigue that have been used since the 1970s [13–19]. As an example, Istomin et al. (2009) [20] conducted X-ray studies on fatigued DSS and showed that on average a relation between the number of fatigue cycles and splits in diffraction peaks originated from the ferrite phases exists.

View all citing articles on Scopus

Present address: National Inst. of Science and Technology, Gaithersberg, MD 20899, U.S.A.

§

Present address: CAP, Trafalgar House, Caversham, Reading, England.

View full text