Evaluation of damage in front of starting notches induced by ultra-short pulsed laser ablation for the determination of fracture toughness in zirconia

Machining a very sharp notch on the surface of ceramics for fracture toughness testing has been a critical issue during many years. In this work, we explore a novel method capable of inducing sharp features with negligible damage with laser pulsed ablation. We study the effect of different laser ablation parameters in the notch length and damage induced in 3 mol% yttria doped zirconia. In front of the notch it is found a very narrow microcracked zone which spreads in the notch direction, whose length only depends on the laser pulse energy; meanwhile the length of the notch is proportional to the energy deposited during the process.