Abstract
The effect of angular and spherical shaped Al2O3 particulates on the precipitation behaviour of 6061 aluminium-matrix composites has been studied using microhardness testing, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The evolution of precipitates at each stage of precipitation corresponding to the DSC-peak was monitored through careful TEM observations. Both the formation and dissolution behaviour of the precipitates in the ageing process in the composites were compared with the unreinforced 6061 matrix alloy. Although an overall accelerated ageing response in the composites was reported, not all stages in the ageing process were influenced by the addition of particulates. However, the precipitation sequence was not altered by the presence of the particulates. The degree of acceleration and the relative proportion of the phase/phases was found to depend on reinforcement parameters such as size, shape and volume fraction. In the composites, higher dislocation densities were observed in the immediate vicinity of the ceramic particles which may have formed due to the large difference in the coefficients of thermal expansion (CTE) between the ceramic particles and the matrix. These CTE-dislocation effects influence the kinetics of precipitation.
Similar content being viewed by others
References
J. M. Papazian,Metall. Trans. 19A (1988) 2945.
P. Appendino, C. Badini, F. Marino andA. Tomasi,Mater. Sci. Eng. A135 (1991) 275.
C. Badini, F. Marino andA. Tomasi,J. Mater. Sci. 26 (1991) 6279.
I. Dutta, S. M. Allen andJ. L. Hafley,Metall. Trans. 22A (1991) 2553.
H. Lee, W. H. Lu andS. L. I. Chan,Scripta Metall. 25 (1991) 2165.
T. Das, S. Bandyopadhyay andS. Blairs,J. Mater. Sci. 29 (1994) 5680.
M. J. Hadianfard, Y-W Mai andJ. C. Healy,ibid. 28 (1993) 3665.
J. P. Unsworth andS. Bandyopadhyay,ibid. 29 (1994) 4645.
G. A. Edwards, G. L. Dunlop andM. J. Couper, in “3rd Australian Forum on MMC”, Conference Proceedings University of New South Wales, Sydney, Australia, 7 December 1992, edited by S. Bandyopadhyay and A. G. Crosky (University of NSW, Sydney, 1992) p. 52.
T. G. Neih andF. F. Karlak,Scripta Metall. 18 (1984) 25.
J. L. Petty-Galis andR. D. Goolsby,J. Mater. Sci. 24 (1989) 1439.
M. D. Skibo andD. M. Schuster, US Pat. 475995, July 1988.
M. J. Couper andK. Xia, in “Proceedings of the 12th Riso International Symposium on Materials Science: Metal matrix Composites — Processing, Microstructure and Properties”, edited by N. Hansen, D. Juul Jenser, T. Leffers, H. Liholt, T. Loren-zen, A. S. Pedersen and B. Ralph (Riso National Laboratory, Denmark, 1991) p. 291.
T. Das, S. Bandyopadhyay andS. Blairs,J. Mater. Eng. Perform. 1 (1992) 839.
E. Ozawa andH. Kimura,Mater. Sci. Eng. 8 (1971) 327.
I. Dutta andS. Allen,J. Mater. Sci. Lett. 10 (1991) 323.
V. A. Phillips andJ. D. Livingston,Philos. Mag. 7 (1962) 969.
H. Cordier andW. Gruhl,Z. Metalkde 56 (1965) 669.
W. F. Smith,Metall. Trans. 4 (1973) 2435.
C. Badini, F. Marino andA. Tomasi,Scripta Metall. 25 (1990) 57.
M. H. Jacobs,Philos. Mag. 26 (1972) 1.
H. J. Rack andR. W. Krezner,Metall. Trans. 8A (1977) 335.
G. Thomas,J. Inst. Metals 90 (1961–62) 57.
D. W. Pashley, J. W. Rhodes andA. Sendrek ibid. 94 (1966) 41
I. Dutta andD. L. Bourell.Scripta Metall. 22 (1988) 829.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Das, T., Munroe, P.R. & Bandyopadhyay, S. The effect of Al2O3 particulates on the precipitation behaviour of 6061 aluminium-matrix composites. J Mater Sci 31, 5351–5361 (1996). https://doi.org/10.1007/BF01159304
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01159304