Residual stress

Indentation hardness

Composite material

Selective laser melting

Metallurgy

Materials science

Corrosion

Scanning electron microscope

Alloy

Optical microscope

Laser peening

Shot peening

Peening

Microstructure

Titanium alloy

Journal of Materials Research and Technology

The ultrasonic shot peening (USP) treatment was adopted to improve the compressive residual stress, microhardness and corrosion resistance of Ti–6Al–4V (TC4) titanium alloy fabricated by selective laser melting (SLM). The optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD) and hardness test were used to investigate the microstructure evolution. The effect of the USP on electrochemical behaviour of the SLM TC4 alloy in a 3.5 wt. % NaCl solution was studied using potentiodynamic polarization. After USP treatment, compressive residual stress was induced and microhardness significantly increased. Proper USP treatment can effectively improve corrosion resistance of the SLM TC4 alloy, which is manifested by the increase in corrosion potential and decrease in corrosion current density.

Effect of ultrasonic shot peening on microstructure evolution and corrosion resistance of selective laser melted Ti–6Al–4V alloy