Crystallographic texture in pulsed laser deposited hydroxyapatite bioceramic coatings

Abstract

The orientation texture of pulsed laser deposited hydroxyapatite coatings was studied by X-ray diffraction techniques. Increasing the laser energy density of the KrF excimer laser used in the deposition process from 5 to 7 J/cm 2 increases the tendency for the c-axes of the hydroxyapatite grains to be aligned perpendicular to the substrate. This preferred orientation is most pronounced when the incidence direction of the plume is normal to the substrate. Orientation texture of the hydroxyapatite grains in the coatings is associated with the highly directional and energetic nature of the ablation plume. Anisotropic stresses, transport of hydroxyl groups and dehydroxylation effects during deposition all seem to play important roles in the texture development.

Elaboration of Monophasic and Biphasic Calcium Phosphate Coatings on Ti6Al4V Substrate by Pulsed Electrodeposition Current

“…Its bioactivity and osteoconductivity can be improved by coating it with calcium phosphate ceramics, especially hydroxyapatite (HAP), which are able to form a real bond with the surrounding bone tissue in vivo. [1][2][3][4] Therefore, various surface treatment techniques have been developed and used to prepare HAP coatings on the implant surfaces of Ti and its alloys; these include, for example, plasma spray, [5,6] sol-gel, [7][8][9] pulsed laser-deposition, [10][11][12] electrophoretic [13][14][15] and electrochemical deposition [16][17][18][19][20][21] methods. This last method has a variety of advantages, such as the low temperature of the process, and control over the thickness and chemical composition of the coatings.…”

Expansion of a multi-component laser-ablated plume

“…Nevertheless crystalline films have been obtained [9][10][11][12][13] under similar experimental conditions.…”

“…HA is deposited onto orthopaedic implants in order to improve the bone-implant contact. Good quality HA coatings are obtained when the ambient gas is water vapour at a pressure of 10-150 Pa [9][10][11][12]. Comprehensive literature can be found in [13].…”

Recent advances in laser surface treatment of titanium alloys

“…However, other coating techniques offer promising results-such as pulsed laser deposition 4 -which takes advantage of the compressive impact of the beam to achieve a higher density. Both techniques can be combined by using APS to project the surface coating and laser surface remelting ͑LSR͒ to consolidate and improve adherence.…”