Ultrasonic impact machining of body surfaces to correct defects and strengthen work surfaces

An ultrasonic impact machining transducer system for thermally machining a metallic workpiece surface by impact of a set of ultrasonically vibrating impacting elements to deform surface and sub-surface areas, comprising in combination:

• an ultrasonic transducer having an abutment surface oscillating at a periodic ultrasonic frequency, and
• an impacting element array comprising a plurality of impacting elements in a set individually arranged to axially move freely over a striking path between an energy supplying contact with the abutment surface for receiving the energy and an energy of impact at the workpiece surface in a vibration mode established by an aperiodic vibration mode of the impacting elements of the set at different phases of the periodic ultrasonic frequency.

Metallic body comprising a surface to be subjected to compressive forces interfacing with a mating surface machined by an ultrasonic impact energy machining process to produce a compressed surface layer of increased strength permitting the compressive forces to approach a maximum strength of the metallic body metal surface.

A metallic workpiece comprising a work surface for compressively interfacing with a mating surface exhibiting a work surface profile obtained by ultrasonic impact machining of the work surface exhibiting a pattern of small area indents compressing the workpiece.

An ultrasonic transducer system for ultrasonic impact machining a metallic object comprising:

• a set of impacting needles,
• an ultrasonically periodically vibrating transducer driving surface having means for propelling individual impacting needles in the set in free axial movement toward a work surface on the metallic object to be machined with an effective amount of kinetic energy to convert to potential energy to deform and compress the metallic object upon impact.

(canceled)

(canceled)

A metallic body comprising:

• a surface having a plurality of indentations therein provided by ultrasonically impacting a set of ultrasonic impact elements against the body in a random and asymmetric ultrasonic mode, the indentations arranged to correspond to possible values of a spacing of a surface vortex flow which forms at the surface by a fluid as the fluid flows about the body.