In situ SEM studies on the effects of particulate reinforcement on fatigue crack growth mechanism of aluminium-based metal-matrix composite
- 86 Downloads
The effects of particulate reinforcement on the fatigue behaviour and fatigue mechanisms of two 6061 aluminium-based metal-matrix composites (MMCs) in three different heattreatment conditions were studied in situ with a scanning electron microscope and compared to the unreinforced alloy in the as-received condition. It was observed that the fatigue properties of the MMCs were influenced by the ceramic particles in two ways: firstly the particles increased the fatigue stress intensity threshold mainly by crack-deflection and crack-closure mechanisms, and secondly, the particles raised the fatigue crack growth rates in the Paris region by providing an easy crack path. The effect of ageing was small on the fatigue stress intensity threshold of MMCs, but for the peak-aged MMCs the fatigue crack growth rates in the Paris region were faster. The mechanism of fatigue crack growth was largely associated with the matrix/particle interface and the linkage with subcracks initiated ahead of the main crack at high applied stress intensity factors.
KeywordsFatigue Stress Intensity Factor Fatigue Crack Growth Crack Path Ceramic Particle
Unable to display preview. Download preview PDF.
- 11.O. Ø. Mouritsen and B. L. Karihaloo, Mater. Forum 15 (1990) 360.Google Scholar
- 12.Y. Murakami, “Stress Intensity Factors Handbook” (Pergamon Press, Oxford, 1986).Google Scholar
- 13.D. R. Williams and M.E. Fine, in “Proceedings of the 5th International Conference on Composite Materials”, edited by W. C. Harrigan, J. Strlef and A. K. Dhingra (1985) p. 639.Google Scholar
- 16.M. J. Hadianfard, PhD thesis, Sydney University, Australia (1995).Google Scholar
- 17.M. J. Hadianfard, J. Healy and Y. W. Mai, in “Proceedings of Advanced Composite 93”, Wollongong, Australia, edited by T. Chandra, A.K. Dhingra (TMS, Warrendale, PA, 1993) pp. 1199–206.Google Scholar
- 19.Duralcan data sheet, Duralcan USA, 10505 Roselle Street, San Diego, CA 92121 (1990).Google Scholar