On the development of a relationship between fractal dimension and impact toughness

Resumo

V-notch Charpy samples of a commercial medium-carbon ferrite-pearlite steel rolled (10% and 25%) at 25, 200, 500 and 700 ºC, wern tested at room temperature to determine fractal dimensions, Df, of the fracture surfaces. The fractal dimensional increment, Df’, as measured by the slit island technique and the impact toughness, KCV, showed a positive relationship, contrary to some previous results. This discrepancy could be explained from the basic features of the different fracture micromechanisms, wich involve a pattern of discrete fractographic structural units, different in size for each case, related to the energy absorption during the fracture process.