Pulsed laser deposition of pseudowollastonite coatings

Pseudowollastonite (alpha-CaSiO3) is a bioactive ceramic material that induces direct bone growth. A process to obtain pseudowollastonite coatings that may be applied to implants is described and evaluated in this work. The coatings were first deposited on titanium alloy by laser ablation with a pulsed Nd:YAG laser tripled in frequency. After deposition, they were submitted to a soft laser treatment with a continuous wave Nd:YAG infrared laser. Coatings were characterised by X-ray diffractometry, Raman spectroscopy, scanning electron microscopy and energy dispersive spectroscopy before and after the laser treatment. As-deposited coatings are composed of pseudowollastonite and amorphous material. They have a porous structure of gathered grains and poor cohesion. After the laser treatment the coatings crystallinity and cohesion are improved. The laser treatment also makes the coatings dense and well adhered to the substrate. Therefore, this two-step process has been demonstrated as a valuable method to coat titanium implants with pseudowollastonite.