Enhanced Bio-compatibility of Ti-6Al-4V by Laser Surface Engineering
|Jyotsna Dutta Majumdar , Indranil Manna|
Indian Institute Of Technology,Kharagpur (IIT), Kharagpur, India
The present study aims at enhancing the wear resistance and bio-compatibility of Ti-6Al-4V by laser surface melting and nitriding. Laser surface treatment has been carried out by melting of sand blasted Ti-6Al-4V substrate using a high power continuous wave DIODE laser with argon and nitrogen as shrouding environment (at a gas flow rate of 5 l/min). Following laser surface treatment, a detailed characterization (microstructure, composition and phase) and property evaluation (wear, corrosion, bio-compatibility) of the surface have been carried out. Laser surface melting increased the volume fraction of acicular (quenched-in a) Ti and decreased the volume fraction of b phase in the microstructure (as confirmed by X-ray diffraction analysis). On the other hand, laser surface nitriding led to formation of dendrites of titanium nitrides. The microhardness is improved to a maximum of 450 VHN (in laser surface melting) and 900-950 VHN (in laser surface nitriding) as compared to 260 VHN of as-received substrate. Surface melting increased the corrosion potential (Ecorr) and primary potential for pit formation (Epp1) significantly as compared to as-received Ti-6Al-4V. However, processed under similar conditions, surface nitriding shifted Ecorr marginally to the nobler direction, and increased Epp1 as compared to Ti-6Al-4V. Biocompatibility behavior showed a better cell viability due to surface nitriding and inferior cell viability due to surface melting as compared to as-received Ti-6Al-4V.
Presentation: Oral at E-MRS Fall Meeting 2006, Symposium J, by Jyotsna Dutta Majumdar
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-07 08:03 Revised: 2009-06-07 00:44