Laser surface modification of electrophoretically deposited hydroxyapatite coating on titanium

Abstract

Laser surface treatment was used on electrophoretically deposited hydroxyapatite (HAP) coatings on Titanium (Ti) to improve interfacial bonding. First, electrophoretic deposition (EPD) was used to produce thick HAP coatings on Ti substrate. Both heat treatment and laser surface treatment were used to create a strong metal-ceramic interface. X-ray diffraction results for laser-treated surface indicated the presence of HAP and Ti phases along with CaTiO3. A second layer of HAP was electrophoretically deposited on laser-treated coatings to improve biological properties further. Our results show that laser surface treatment can eliminate delamination of weak interface of HAP coatings by forming a strong Ti-HAP composite layer at the interface. The coating hardness increased to 582±98 Hv compared with the base metal hardness of 306±20 Hv. Bone cell-material interactions for both laser treated and untreated samples with human osteoprecursor cells showed no sign of toxicity due to laser processing, and increased bioactivity due to HAP coatings. © 2008 The American Ceramic Society.