Fatigue crack propagation resistance of cemented carbides

It is Studied the fatigue crack growth behavior of two grades of WC-Co ceme nted carbides, both with a 10%(wt) of Co but with different carbide grain s ize, 0,8 and 2,5 tm. Crack growth kinetics, measured under different load r atios, 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 a pplied stress intensity factor, K-max and DeltaK respectively, within an eq uation of the form da/dN= f (K-max DeltaK) It is observed a significant dep endence with respect to K-max, yielding evidence of the prominence of stati c modes of rupture. Under these considerations, the fatigue crack growth se nsitivity of the materials studied is evaluated. Finally, the damage mechan isms associated with stable and unstable fatigue crack propagation are anal yzed.