To investigate the machining effect of ultrasonic honing microjets on a titanium-tantalum alloy surface, a cavitation microjet flow impingement model was established using the smoothed particle hydrodynamics-finite element method (SPH-FEM) coupling method including the effects of wall elastic-plastic deformation, the ultrasonic field and the honing pressure field. Simulation analysis was conducted on a single impact with different initial speeds and a continuous impact at a constant initial speed. The results showed that the initial speed of the microjet needed to reach at least 580 to 610 m/s in order to obtain an obvious effect of the single impact. The single impact had almost no effect at low speeds. However, when the microjet continuously impacted the same position, obvious pits were produced via a cumulative effect. These pits were similar to that obtained by the single impact, and they had the maximum depth at the edge rather than the center. With the increase in the microjet's initial speed, the total number of shocks required to reach the same depth gradually decreases. When the number of impacts is large, with the increase in the number of impacts, the growth rate of the maximum pit depth gradually slows down, and even shows no growth or negative growth at some times. Using the continuous impacts of the microjet by prolonging the processing time can enhance titanium-tantalum alloy machining with ultrasonic honing for material removal.
Keywords: acoustic cavitation; microjet impact; smooth particle fluid dynamics; ultrasonic honing.