Fatigue crack growth rate and propagation mechanisms of SiC particle reinforced Al alloy matrix composites
Aircraft Engineering and Aerospace Technology
ISSN: 0002-2667
Article publication date: 14 December 2023
Issue publication date: 7 March 2024
Abstract
Purpose
This study aims to investigate the fatigue crack propagation behavior of SiC particle-reinforced 2124 Al alloy composites under constant amplitude axial loading at a stress ratio of R = 0.1. For this purpose, it is performed experiments and comparatively analyze the results by producing 5, 10, 15 Vol.% SiCp-reinforced composites and unreinforced 2124 Al alloy billets with powder metallurgy (PM) production technique.
Design/methodology/approach
With the PM production technique, SiCp-reinforced composite and unreinforced 2124 Al alloy billets were produced at 5%, 10%, 15% volume ratios. After the produced billets were extruded and 5 mm thick plates were formed, tensile and fatigue crack propagation compact tensile (CT) samples were prepared. Optical microscope examinations were carried out to determine the microstructural properties of billet and samples. To determine the SiC particle–matrix interactions due to the composite microstructure, unlike the Al alloy, which affects the crack initiation life and crack propagation rate, detailed scanning electron microscopy (SEM) studies have been carried out.
Findings
Optical microscope examinations for the determination of the microstructural properties of billet and samples showed that although SiC particles were rarely clustered in the Al alloy matrix, they were generally homogeneously dispersed. Fatigue crack propagation rates were determined experimentally. While the highest crack initiation resistance was achieved at 5% SiC volume ratio, the slowest crack propagation rate in the stable crack propagation region was found in the unreinforced 2124 Al alloy. At volume ratios greater than 5%, the number of crack initiation cycles decreases and the propagation rate increases.
Originality/value
As a requirement of damage tolerance design, the fatigue crack propagation rate and fatigue behavior of materials to be used in high-tech vehicles such as aircraft structural parts should be well characterized. Therefore, safer use of these materials in critical structural parts becomes widespread. In this study, besides measuring fatigue crack propagation rates, the mechanisms causing crack acceleration or deceleration were determined by applying detailed SEM examinations.
Keywords
Acknowledgements
The authors would like to thank Erciyes University for their financial support of the present study (Project no: FYL-2014–5612 and FBA-2016–6416).
Declarations: The authors declare that they have no conflict of interest.
Citation
Karci, A., Erturun, V., Çakir, E. and Çam, Y. (2024), "Fatigue crack growth rate and propagation mechanisms of SiC particle reinforced Al alloy matrix composites", Aircraft Engineering and Aerospace Technology, Vol. 96 No. 2, pp. 185-192. https://doi.org/10.1108/AEAT-01-2023-0010
Publisher
:Emerald Publishing Limited
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