Simulation of the electric shock peening of Ti-6Al-4V alloy in oil

A peening method utilizing the dielectric breakdown in a liquid is presented as an alternative to current shot peening, laser shock peening and waterjet peening. These techniques are inefficient or even inapplicable for a deep notch which is typically the origin of a fatigue crack. Simulations of dielectric breakdown peening of Ti-6Al-4V alloy in oil triggered by a drop of water show that the breakdown energy is effectively delivered to the deep root of a notch, and it builds up a healthier, residual compressive zone. The major mechanism responsible for the peening is found to be the high speed, compressible impact of the oil, with a weak contribution from the shock wave propagated through the oil.