Methods: The sol-gel technique obtained four steps: 1.pre-treatment(sanding,washing,activation);2.the preparation of sol:mixed titanium chloride,alcohol,water and stirred rapidly.Some small charged particles produced by the hydrolytic reaction from colloidal solution, because these particles with similar electric charges repelled each other, and could not further combine bigger particle precipitates. Mixed these colloids and some dissovent was unable to dissolve in water, and they would congeal into extremely small particles, diameter usually was 5um; 3.coating;4.heat treatment:desiccation 30min,condensation 60min,agglutination 120min.As the temperature was increasing, Ti and organism formed a kind of cubic net structure, and the atoms of Ti were left.
Results: After coating titanium, the surface of Ni-Cr alloy looked shallow golden. According to ISO10289, it was smooth without particles, blisters and fragments.
Conclusion: With sol-gel method, titanium would be coated on the surface of Ni-Cr alloy.