Product Code: ICA13_304

Bioactive Glass Coatings on Al2O3-Zro2 Composite Substrates by Laser Cladding for Orthopaedic Applications
Authors:
M. Angeles Montealegre, Aimen- Technology Centre; PorriñO Spain
Francesco Baino, Politecnico Di Torino; Torino Italy
Jorge Luis Arias, Aimen- Technology Centre; PorriñO Spain
Joaquim Minguella, FundacióNcim C/ Llorens I Artigas, 12; Barcelona Spain
Chiara Vitale-Brovarone, Politecnico Di Torino, 24; Torino Italy
Martyn Marshall, Glass Technology Services Ltd. 9 Churchill Way; Sheffield Great Britain
Presented at ICALEO 2013

Alumina-zirconia (Al2O3-ZrO2) composite is widely used as a ceramic material in implants for orthopaedic applications due to its high mechanical resistance. Laser cladding has proven to be able to apply bioactive glass (BG) coatings on titanium implants1 and to produce small BG implants. In this work, the ability of this technology to produce macroporous bioactive glass-ceramic coatings on Al2O3-ZrO2 composite is studied.
Sintered Al2O3-ZrO2 substrates were coated by laser cladding, using two different BGs as precursor powders.
Composition (mol.%) of BG powders.
BG SiO2 CaO Na2O P2O5 Al2O3 B2O3
3c 57 30 6 -- 7 --
3u 50 35 7 6 -- 2
Laser cladding experiments were performed with two lasers: a CO2 laser (0.5 mm beam diameter) to produce dense coatings, and a single mode fiber laser (11 m beam diameter) to obtain a macroporous structure onto the ceramic surface. Also two ways were studied to melt the powder onto the ceramic surface: preplacing the powder on the surface, and blowing it with a powder injection nozzle (coaxially with incident laser beam).
Both dense coatings and macroporous structures were analyzed by optical and scanning electron microscopy. The composition of the different phases was analyzed by an energy dispersive X-ray spectroscopy microprobe, attached to the SEM, and X-ray diffraction.
As a conclusion, Laser cladding has shown to be a suitable and promising technology to produce both bioactive glass-ceramic coatings and macroporous structures onto Al2O3-ZrO2 ceramic.
ACKNOWLEDGMENTS
The research leading to these results has received funding from the EU- FP7/2007-2013 under grant agreement n° [286548/MATCh project].