Regularities of the Intensifying Effect of Ultrasonic Treatment on Titanium Alloy Pickling

The effect of ultrasonic treatment under conditions of acoustic cavitation on the pickling and brightening of titanium and its alloys in acidic solutions containing various oxidants and in alkaline solutions is studied. It is shown that the liquid cavitation close to the metal surface pickled intensifies the pickling and brightening processes several times. The reasons for the effect are discussed. Intense acoustic cavitation can make water molecule split and produce free radicals and hydrogen peroxide. When collapsing, cavity bubbles eliminate capillary limitations and intensify the access for pickling solution to the oxidized metal surface. While pulsating, they promote degassing the solution and removing hydrogen bubbles from oxidized metal surface, thus freeing the access for solution. The cavitating ultrasonic intensification of industrial surface treatment of titanium and its alloys is recommended.