Quantification of microdamage phenomena during tensile straining of high volume fraction particle reinforced aluminium

Particle reinforced composites are produced by infiltrating ceramic particle beds with 99.99% Al. Resulting materials feature a relatively high volume fraction (40-55 vol. pet) of homogeneously distributed reinforcement. The evolution of damage during tensile straining of these composites is monitored using two indirect methods; namely by tracking changes in density and in Young's modulus. Identification and quantification of the active damage mechanisms is conducted on polished sections of failed tensile specimens: particle fracture and void formation in the matrix are the predominant damage micromechanisms in these materials. The damage parameter derived from the change in density at a given strain is found to be one to two orders of magnitude smaller than the parameter based on changes in Young's modulus. A simple micromechanical analysis inspired by the observed damage micromechanisms is used to correlate the two indirect measurements of damage. The predictions of this analysis are in good agreement with experiment. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. AII rights reserved.

[1]  A. Mortensen,et al.  On the use of considere"s criterion in tensile testing of materials which accumulate internal damage , 1999 .

[2]  B. Derby,et al.  Stiffness of particulate reinforced metal matrix composites with damaged reinforcements , 1999 .

[3]  L. Gibson,et al.  The compressive behaviour of porous copper made by the GASAR process , 1997 .

[4]  J. Bouix,et al.  Chemical reactivity of aluminium with boron carbide , 1997 .

[5]  T. Clyne,et al.  Effects of reinforcement content and shape on cavitation and failure in metal-matrix composites , 1993 .

[6]  D. Wilkinson,et al.  Plastic flow and fracture of a particulate metal matrix composite , 1996 .

[7]  H. E. Boyer,et al.  Metals handbook; desk edition , 1985 .

[8]  Peter Cloetens,et al.  Characterization of internal damage in a MMCp using X-ray synchrotron phase contrast microtomography , 1999 .

[9]  W. Poole,et al.  Experimental measurements of damage evolution in Al-Si eutectic alloys , 1998 .

[10]  R. Ratcliffe,et al.  The measurement of small density changes in solids , 1965 .

[11]  M. Vedani,et al.  Damage and Ductility of Particulate and Short-Fibre Al-Al2O3 Composites. , 1996 .

[12]  Jean Lemaitre,et al.  A Course on Damage Mechanics , 1992 .

[13]  T. Clyne,et al.  Effect of test conditions on cavitation and failure during tensile loading of discontinuous metal matrix composites , 1994 .

[14]  Samuel J. Schneider,et al.  Ceramics and glasses , 1991 .

[15]  Somnath Ghosh,et al.  Particle fracture simulation in non-uniform microstructures of metal-matrix composites , 1998 .

[16]  B. Derby,et al.  Acoustic emission from a SiC reinforced Al-2618 metal matrix composite during straining , 1997 .

[17]  A. Kennedy,et al.  The effect of processing on the mechanical properties and interfacial strength of aluminium/TiC MMCs , 2000 .

[18]  M. Enoki,et al.  A new method based on simultaneous acoustic emission and in-situ sem observation to evaluate the fracture behavior of metal matrix composites , 1997 .

[19]  Owen Richmond,et al.  An experimental–computational approach to the investigation of damage evolution in discontinuously reinforced aluminum matrix composite , 1999 .

[20]  B. Derby,et al.  In situ scanning electron microscope studies of fracture in particulate-reinforced metal-matrix composites , 1994, Journal of Materials Science.

[21]  J. R. Griffiths,et al.  Damage by the cracking of silicon particles in an Al-7Si-0.4Mg casting alloy , 1996 .