Effect of intermetallic particles and grain boundaries on short fatigue crack growth behaviour in a cast Al–4Cu–3Ni–0.7Si piston alloy
journal contributionposted on 07.09.2017, 14:01 by T.O. Mbuya, Y. Gu, Rachel ThomsonRachel Thomson, Philippa A.S. Reed
The short fatigue crack growth behaviour in a model cast aluminium piston alloy has been investigated. This has been achieved using a combination of fatigue crack replication methods at various intervals during fatigue testing and post-mortem analysis of crack profiles. Crack–microstructure interactions have been clearly delineated using a combination of optical microscopy, scanning electron microscopy and electron backscatter diffraction. Results show that intermetallic particles play a significant role in determining the crack path and growth rate of short fatigue cracks. It is observed that the growth of short cracks is often retarded or even arrested at intermetallic particles and grain boundaries. Crack deflection at intermetallics and grain boundaries is also frequently observed. These results have been compared with the long crack growth behaviour of the alloy.
The ﬁrst author acknowledges the Faculty of Engineering and the Environment of the University of Southampton and the University of Nairobi for their ﬁnancial support when this work was carried out.
- Aeronautical, Automotive, Chemical and Materials Engineering