Interface reactions and fracture behaviour of fibre-reinforced Mg/Al alloys

authored by
A. Feldhoff, E. Pippel, J. Woltersdorf
Abstract

In the composite system carbon fibre/magnesium alloy the interface reactivity was varied over a wide range by adding different amounts of the alloying element aluminium (alloys: AM20, AZ91) and by using carbon fibres of different surface properties (fibres: M40J, T300J). The structure and composition of interlayers in these composites down to the atomic scale as well as their effect on the mechanical properties were studied systematically by the combination of high-voltage electron microscopy, high-resolution electron microscopy, energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy with scanning electron microscope in situ bending tests. As resulting microstructure and nanochemistry correlate with the micromechanical fracture behaviour of the metal matrix composites, the interface reactivity can be used as a parameter governing the composite properties. In addition to precipitates of aluminium carbide, strongly influencing the fracture behaviour, there are also graphitic carbon ribbons and layers of nanocrystalline magnesium oxide at the fibre/matrix interface. Increasing the reactivity of the composite system, three characteristic modes of fracture behaviour are observed: single fibre pullout, bundle fracture (the optimum composite) and brittle failure.

Organisation(s)
Institute of Physical Chemistry and Electrochemistry
External Organisation(s)
Max Planck Institute of Microstructure Physics
Type
Article
Journal
Journal of microscopy
Volume
185
Pages
122-131
No. of pages
10
ISSN
0022-2720
Publication date
1997
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Pathology and Forensic Medicine, Histology
Electronic version(s)
https://doi.org/10.1046/j.1365-2818.1997.d01-611.x (Access: Unknown)