2.4.3. Shot Peening

The process of shot peening resembles abrasive shot blasting but uses metallic beads to treat the surface of the samples. In the present case, a small hole was drilled at one end of the samples to facilitate their hanging on a rotary unit and allowing the shot peening process in an automated chamber. Spherical stainless-steel beads with diameters ranging from 0.2 to 0.3 mm were propelled at the samples using a 2500 rpm turbine working at a pressure of 5 bar during a total treatment time of 10 min.

A summary of the post-processing techniques and experimental conditions used in the present study can be found in Table 1.


**Table 1.** Post-processing techniques and procedures applied to Ultem pieces.
