Laser treatment of plasma sprayed HA coatings

Laser treatment was conducted on plasma sprayed hydroxyapatite (HA) coatings using a Nd-YAG pulse laser. Various laser parameters were investigated. The results showed that the HA surface melted when an energy level of ≥2 J and a spot size of 2 mm was employed during continuous scanning. The melted structure displayed a multi-layered porous structure. The size range of these pores was about 30–150 μm. These pores have the propensity to promote osseo-induction. However, when the spot size was increased to 3 mm, the coating was found to display melted structure at energy levels of >6 J. XRD results for the laser treated coating showed increased crystallinity of the HA phase. Favourable amount of crystalline HA was found when the laser pulse energy <5 J and a laser spot size of 3 mm was employed.