DR. THOMAS OCHUKU MBUYA
BSc, MSc Mechanical Engineering, University of Nairobi, PhD Mechanical Engineering, University of Southampton
Tel. +254 (0) 20 4913527; 0703 133 990 (mobile); tmbuya@uonbi.ac.ke
Tel. +254 (0) 20 4913527; 0703 133 990 (mobile); tmbuya@uonbi.ac.ke
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.