Effect of vibratory assisted severe surface plastic deformation (VA–SPD) method on Ti6Al4V alloy: a mechanical characterization

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Selçuk E., Öksüz K. E., Şimşir M., Ünal O.

Gümüşhane Üniversitesi Fen Bilimleri Dergisi, cilt.16, sa.3, ss.968-981, 2026 (TRDizin)

Özet

Vibratory-assisted severe surface plastic deformation (VA–SPD) is a relatively new surface modification technology utilized to enhance the mechanical properties of components in the automotive and aircraft industries. This process generates internal motion within the equipment, transmitting energy to the processing chamber and the shots to induce high-frequency vibrations. In this study, the effects of the VA–SPD process on the Titanium alloy (Ti6Al4V) were investigated. The peening treatments were performed for 2 hours at a vibration frequency of 40 Hz using two different steel shot diameters (1 mm and 3 mm). Microstructural characterizations of the treated and untreated Ti6Al4V samples were conducted via Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses. The full width at half maximum (FWHM) and estimated crystallite size values were calculated from the XRD data. Mechanical evaluations included cross-sectional microhardness measurements on both unpeened and peened specimens. Wear tests were carried out under varying loads of 42 N, 62 N, and 82 N to evaluate the friction coefficient for each condition. Furthermore, surface roughness profiles were analyzed using Ra, Rq, and Rz parameters across all process conditions. The results demonstrated that the VA–SPD process enhanced the surface integrity of the peened specimens by effectively mitigating the residual machining marks present on the as-received (AR) material. Additionally, under the highest wear load of 82 N, the friction coefficient of the peened specimens exhibited a noticeable decrease compared to the unpeened specimen. Overall, the findings suggest that using a 1 mm shot size provides more favorable outcomes for improving mechanical behavior.

Keywords: Microhardness, Microstructure, Severe plastic deformation, Surface roughness, Ti6Al4V, Wear