Fatigue crack propagation resistance of cemented carbides

It is Studied the fatigue crack growth behavior of two grades of WC-Co cemented carbides, both with a 10%(wt) of Co but with different carbide grain size, 0,8 and 2,5 tm. Crack growth kinetics, measured under different load ratios, is described using an alternative form to the Paris equation. Hence, it is used a model that takes into account both maximun and range of the applied stress intensity factor, K-max and DeltaK respectively, within an equation of the form da/dN= f (K-max DeltaK) It is observed a significant dependence with respect to K-max, yielding evidence of the prominence of static modes of rupture. Under these considerations, the fatigue crack growth sensitivity of the materials studied is evaluated. Finally, the damage mechanisms associated with stable and unstable fatigue crack propagation are analyzed.