The relationship between the microstructure and corrosion behaviour of Ti6Al4V alloy and laser-clad
commercially pure (CP) Ti coating was investigated. The microstructure, phases and properties of the
clad layers were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and
energy dispersive spectrometry (EDS). Electrochemical measurement techniques including open circuit
potential (OCP) and potentiodynamic polarisation were used to evaluate the corrosion behaviour of
Ti6Al4V alloy in 0.1 M oxalic acid solution and the results compared to the behaviour of laser-clad CP Ti at
varying laser scan speed. Results showed that laser-clad CP Ti at scan speed of 0.4 m/min formed a good
cladding layer without defects such as cracks and pores. The phase present in the cladding layer was
mostly a0
-Ti. The microstructures of the clad layer were needle like acicular/widmanst€
atten a. An
improvement in the microhardness values was also recorded. Although the corrosion potentials of the
laser-clad samples were less noble than Ti6Al4V alloy, the polarisation measurement showed that the
anodic current density was lower and also increases with increasing laser scanning speed.