The features of the surface hardening of titanium alloy Ti–6Al–4V manufactured by metallurgical (hot rolling (HR)) and additive selective laser melting (SLM) methods are investigated, using two types of ultrasonic installations, which provide different modes of excitation of a vibration chamber filled with steel balls, namely, high-frequency ball hardening, i.e., surface mechanical attrition treatment (SMAT), and a vibration chamber with oscillations of its bottom and walls. It is shown that a surface roughness reduction, the formation of compressive residual stresses and significant hardening can be achieved regardless of the initiating scheme of ball impacts in the used ultrasonic vibration chambers, if certain optimal processing modes are selected. Within 4 minutes of treatment using the SMAT unit and the vibration chamber, the HR samples are strengthened by 22.6% (4.72 GPa) and 24.9% (4.81 GPa), respectively. The strengthening is due to the formation of residual compressive stresses (of -1560 MPa) during processing in the vibration chamber compared to SMAT (of -1240 MPa), the refinement of α- (of 14-19 nm) and β-phase (of 36-63 nm) crystallites compared to the initial state (of 150 nm and 174 nm, respectively). The SLM samples after SMAT and the vibration chamber undergo strengthening by 51% (6.61 GPa) and 46.7% (6.41 GPa), respectively, compared to the initial state (4.37 GPa). Compared to SMAT unit, the proposed vibration chamber allows producing both longitudinal vibrations of its bottom and concentric vibrations of the walls that increases the efficiency of stable and controlled express processing of parts and assemblies of complex shape, as well as flat and thin metal parts such as engine blades.