Issue 37

M. S. Raviraj et alii, Frattura ed Integrità Strutturale, 37 (2016) 360-368; DOI: 10.3221/IGF-ESIS.37.47 363 be assessed. Also by observing the fractographs the nature of fracture such as ductile and brittle fracture can be distinguished. Figure 4 : Crack length vs. Number of cycles for various Al6061-TiC composites typically for a/W = B/W =0.5. Figure 5 : da/dN vs . ΔK for various Al6061-TiC composites with typically for a / W = B / W =0.5. R ESULTS AND DISCUSSION he fatigue pre-crack should provide the occurrence of cracking at right place for all CT specimens of various Al6061-TiC composites and B / W ratios of a / W =0.5. During fatigue pre-cracking of the specimens, the increase in the crack length from 10.2mm to 12.7mm was measured with respect to the number of cycles for a load range ( R ) of 0.1. Fig. 4 shows the variation of crack length versus number of cycles for CT specimens of a / W = B / W =0.5 with various wt% TiC particles. It is clearly seen from Fig. 4 that number of cycles (N) increased with weight percentage of TiC in the composites. The nature of variation of crack length versus number of cycles is similar to the earlier work of Mohanty et . al . [17], which was carried out for single edge notch specimen of Al7020-alloy. As the crack propagate in the T