Corrosion behaviour of Ti-10Nb-10Zr-5Ta alloys in artificial saliva solution with fluoride content

Ti-10Nb-5Zr-5Ta alloy was produced in levitation melting furnace with cold crucible in argon protective atmosphere. This alloy was chosen as a possible candidate to replace the Ti6Al4V alloy in dentistry. To prove this, the corrosion behaviour of the Ti-10Nb-5Zr-5Ta alloy in NaF enriched saliva with different pH values was investigated. The addition of fluoride ions in acidic saliva (pH = 2) was found to be unfavorable to the corrosion behaviour of the alloy. NaF addition led to an increase in the corrosion rate, whatever the pH of the solution. The high degradation rate was found for the alloy immersed in fluoride enriched acidic saliva. The morphology of the alloy was more significantly changed by addition of NaF than by modification of the saliva pH. For pH = 7, addition of NaF in saliva did not affect too much the surface roughness of the alloy.