Any stress reduction is associated with microplastic deformation of atom. This can be achieved by injecting the extra energy in the job.
During the process of thermal stress relieving, the value of residual stress gets higher than the yield stress value at relieving temperature which makes the material to immediately undergo plastic deformation so as to reduce the residual stress value. By mechanically means, the vibration energy is exerted into the work piece to make the applied stress superimposed on the existing residual stress. The resultant stress value passes through the yield point of the material and will endure plastic deformation resulting in the reduction of residual stress value. The energy injected should have enough magnitude to activate the stress atom to cross the yield point. To achieve this mark, the vibration energy is injected at natural frequency of the work piece.
