Strain Rate Dependence of Fracture Toughness (JIC) and Ductility

In most cases in engineering practice, fracture initiation in metals and alloys is experimentally determined under slow loading conditions. However for materials with strong temperature and strain rate dependence, the fracture toughness usually decreases with decreasing temperature and increasing loading rates. It is thus important to obtain a quantitative correlation between ductility and fracture toughness of these materials as a function of temperature and through a wide range of loading rates. Experimental data in these ranges reveals a transition region from high to low values of fracture toughness.