Quantitative study of correlation between fracture surface roughness and fatigue properties of composites

Effects of particle size, particle volume fraction and matrix composition on the fatigue crack growth resistance of Al alloy/Al alloy + SiCp bimaterials

“…The fractographs were taken at applied DK values of 5 and 7 MPa m 1=2 (immediately before the interface) for both the 'composite only' and the composite side of the bimaterial. In the 'composite only', the trend observed is an increase in the fracture surface roughness with applied DK, as already reported by several authors [33][34][35]. According to McEvily et al [34], the fracture surface roughness increases with DK because the crack wake experiences fewer closure cycles as DK increases and hence there is less cumulative wear.…”

“…According to McEvily et al [34], the fracture surface roughness increases with DK because the crack wake experiences fewer closure cycles as DK increases and hence there is less cumulative wear. Additionally, the increase in K max increases the probability of particle damage and of microcracking ahead of the crack tip, and this may create a preferential path for crack growth that increases the surface roughness [35,36]. However, in the bimaterial, the opposite is observed; the surface roughness decreases as the applied DK increases.…”

On the influence of imaging conditions and algorithms on the quantification of surface topography

“…The fractal dimension is often used as a global topometry parameter (Li et al ., 1995; Li et al ., 1996), despite the fact that its use for characterizing surfaces is limited (Wendt & Blumenauer, 1999). The fractal dimension is estimated not only on height profiles extracted from three‐dimensional images, but also from vertical cuts through fracture surfaces and the application of various methods (Balankin et al ., 2000).…”