The UIT system is an electromechanical process where ultrasonic energy is converted into mechanical energy. When applied to metal fabricated structures, UIT imparts compressive residual stress, mitigates harmful tensile stress, modifies weld toe geometry, and improves grain structure.
UIT delivers an alternative to other methods of peening to modify weld toe geometry and impart beneficial compressive residual stress.
The Magnetorestrictive technology and its application is faster than most peening processes and transfers less rebound energy back to the operator which reduces operator fatigue and improves productivity.
PHYSICS OF UIT
UIT has the energy to plastically deform the surface of the metal being treated down to the depth of up to 1.5 mm and induce compressive stresses down to between 3 - 5 mm.
The ultrasonic transducer drives indenter pins using ultrasonic oscillation equal to or greater than 25kHz to plastically deform the surface of metals while mitigating harmful tensile stresses and imparting compressive residual stress to depths greater than 4mm.
Stress map – yellow indicates tensile stress, blue indicates compressive stress
Indenter pins being driven by an ultrasonic transducer activates the resonant frequency of the metal in the welded structure which relaxes tensile created during welding and imparts compressive residual stress within the heat affective zone (HAZ).
This process reduces stresses formed during welding and weld solidification mitigating harmful tensile stresses.
Stress chart for a steel specimen after argon-arc welding (in the specimen center)
MECHANISM OF GRAIN REFINEMENT
GRAIN SIZE: Homogenous (≈10µm)
GRAIN ORIENTATION: Random
GRAIN SIZE: Ultrafine in surface (0.5µm)
GRAIN ORIENTATION: Layered