Bioactivation Of Pure Titanium Surface By Improved Acid-Alkali Two Steps Approach

The text treated the surface of Ti through improved acid-alkali two steps approach. Result of SBF soaking was regarded as evaluation level of Ti surface bioactivity. The text studied technological parameter to effect rule of bioactivity. Phase constituent,rough state,surface morphology and surface content were fully shown by analysis test method of XRD,AFM,SEM and EDS. After soaking, bonding strength between Ca-P coating and Ti matrix was tested by direct tension method. Comprehension of bioactivity and bonding strength finally determined the best bioactivation technology.Improved acid-alkali two steps approach technology divided acid treatment and alkali heat treatment. The best acid treatment technology was mixing solution of 18%HCl and 3%HF as volume ratio 3:1. The best mixing alkali heat treatment technology was mixing solution of 5mol/L NaOH and 0.02mol/L Ca(OH)2 at 90℃for 24 hours and following at 600℃and holding time for 1h .Improved acid-alkali two steps approach technology shortened the Ca-P coating forming time. Result of SBF soaking at 37℃showed that surface formed HA coating as soaking 1day. Coating was integrated. Grains were fine and uniform. Ca/P was 1.61 near to 1.67 of human bone. The result of direct tension showed that bonding strength between Ca-P coating and Ti matrix was 23.35～25.42MPa.After Ti was treated by improved acid-alkali two steps approach, Ti surface was net porous structure. Phases of surface mainly were Rutile,CaTiO3 and a few Anatase. Ti samples of activation treatment were soaked in SBF. Surface generated hydrolyzation reaction and produced Ti-OH base group of negative electrification. At the same time, Ca²⁺ irons were released. Hydrolyzation reaction improved OH- amout and negative electricity and made solubility product of Ca²⁺, PO₄^3- and OH- increase and reach a certain supersature. It provided advantage situation for nuclei.