Research On The Process And Properties Of Porous Titanium Alloy Fabricated By Laser Solid Forming

In order to modify the stress shielding which is caused by the different elastic modulus between the replacer and the bone and improve the biocompatibility of pure titanium, Laser Solid Forming Technology was used to fabricate porous titanium bulk material in this paper. The effect of laser process parameters on the pore structure, porosity and compression properties of porous titanium were studied.Besides, alkali treatment and alkali-precalcification treatment were used to further improve the bioactivity. The mechanism of inducing apatite was analyzed. The main conclusions were drawn as follows:(1)The size of single-pass cladding was influenced by process parameters seriously. Process parameters also played an important role in the porosity of porous titanium. With the laser power increased, the porosity decreased, with translation distance of the laser and scan speed increased, the porosity increased.(2)The porous titanium with a porosity of 38 to 54% had been fabricated. With the porosity increased, there was a sharp decline in elastic modulus and yield stress. Yield stress decreased from 100MPa when the porosity is 38.0% to 38MPa when 54.1%, the elastic modulus decreased from dense metallic titanium 110GPa to 2-10GPa, which adjusted to the requirements of implant (3-60Gpa).(3)By alkali and alkali-precalcification treatment, the surface of porous titanium formed a porous structure, accelerated the deposition rate and shorted the forming time of apatite, which showed a significant improvement of bioactivity. The activation effect of alkali-precalcification treatment was better than alkali treatment. The alkali-precalcification treatment porous titanium generated the hydroxyapatite layer for 7 days.