Abstract
The functional performance of laser assisted cold sprayed (LACS) commercially pure ( CP) grade 1 titanium
coatings was elucidated in terms of its mechanism of densification, microstructural evolution and corrosion resistance as the
deposition temperature and scanning speed were altered by employing optical microscopy (OM) and potentio-dynamic
polarization technique. The outcome of this study indicates that the densification mechanism of the coating was mainly
influenced by the ratio of the processing temperature (T) and the scanning speed (SS) which is designated as . The
attainment of the optimised functional properties of the coatings could be attributed to the thermal shear in the titanium film
as well as its solid state inter-particulate consolidation resulting from localised thermal gradient which was induced
between the ductile titanium particles and the brittle oxide film covering it at the optimum laser-gas-material interaction
obtained at 600oC/10mm/s coupled with the adiabatic shearing of the particles upon impact at the deposition site. It was
also established that microstructural porosity and cracks resulted from the increased lifetime of the liquid phase under suboptimal
processing conditions which allowed more time for the propellant gas to initiate bubble formation within the
coating’s microstructure. In addition, non-optimal parameters failed to attain the most desirable microstructural properties
and corrosion resistance for the coatings. Finally, key factors in optimising LACS process parameters in order to achieve
fully dense coatings are outlined.