Method and apparatus for surface strengthening of blisk blades

A method for surface strengthening of blisk blades, comprising:

• providing a container at least partially filled with a liquid to provide a liquid bath for receiving a blisk blade;
• inserting at least a portion of a blisk blade to be surface strengthened into the liquid bath;
• providing a jetting unit having a pair of parallel spaced apart liquid jet tubes for positioning on opposite sides of the blisk blade, each connected to a supply of high-pressure liquid, each liquid jet tube having a plurality of nozzle openings equidistantly disposed along a longitudinal direction of the liquid jet tube to produce high-pressure liquid jets penetrating the liquid bath in a direction toward a surface of the blisk blade, the nozzle openings of each of the pair of liquid jet tubes being aligned with and directed toward counterpart nozzle openings on an other of the pair of liquid jet tubes;
• inserting the jetting unit into the liquid bath with the each of the pair of liquid jet tubes positioned on opposite sides of the surface of the blisk blade and simultaneously injecting the high-pressure liquid jets from the liquid jet tubes into the liquid bath toward the opposite sides of the surface of the blisk blade to generate cavitation bubbles in the liquid bath on a periphery of the high-pressure fluid jets;
• causing the cavitation bubbles to implode near the surface of the blisk blade to produce micro jets that create plastically formed depressions having rounded edges on the surface of the blisk blade;
• and
• providing a manipulator connected to the jetting unit for positioning each of the liquid jet tubes at an equal spacing from the opposite sides of the surface of the blisk blade, the manipulator controllable to traverse the jetting unit in X, Y and Z-directions and swivel about a vertical axis and a horizontal axis with respect to the blisk blade to cause the high-pressure liquid jets to traverse a curvature of the surface of the blisk blade while maintaining the equal spacing.