Effect of amorphous calcium phosphate coatings on tribological properties of titanium grade 4 in protein-free artificial saliva

Influence of Anodizing Conditions on Biotribological and Micromechanical Properties of Ti–13Zr–13Nb Alloy

“…Based on the friction coefficient, the kinetic coefficient of friction (µ k ) was determined, which took the smallest value of 0.86(8) for the surface of the Ti–13Zr–13Nb alloy with a 2G ONT layer ( Figure 10 ). A similar value of µ k of 0.86(6) and 0.87(3) was determined for sandblasted [ 15 ] and sandblasted and sterilized [ 16 ] grade 4 titanium, respectively.…”

“…Average material volume consumption (V m ) took the lowest value of 8.20(4)·10 −4 mm 3 N −1 m −1 for the electrochemically unoxidized surface of the Ti–13Zr–13Nb alloy ( Figure 8 b). The obtained V m value was twice as high as compared to the average material volume consumption for mechanically polished grade 4 titanium [ 15 ], 16 times higher than V m for sandblasted grade 4 titanium [ 15 ], and 11 times higher than for sandblasted and steam-sterilized grade 4 titanium [ 16 ], subjected to biotribological wear test under comparable conditions in protein-free artificial saliva. The obtained results indicate that the value of V m increased after the anodizing process of the Ti–13Zr–13Nb alloy in a solution of 0.5% HF, 1M (NH 4 ) 2 SO 4 + 2% NH 4 F, and 1M C 2 H 6 O 2 + 4% NH 4 F. The highest value of Vm equal to 1.79(9)·10 −3 mm 3 N −1 m −1 was observed for the 2G ONT layer, which was very close to the V m obtained for the 3G ONT layer within the limit of error ( Figure 8 b).…”

“…The mechanism of biotribological wear of ONT layers on the Ti–13Zr–13Nb alloy substrate in Ringer’s solution is based on the breaking of oxide nanotubes and their densification in the outer part of the oxide layers according to the wear mechanism of three-body abrasive wear [ 15 , 16 ]. In the proposed mechanism, between the surface of the Ti–13Zr–13Nb alloy with a layer of ONTs (body 1) and the surface of the ZrO 2 ball (body 2), there are particles of worn material (body 3), that act as a carrier abrasive ( Figure 12 ).…”

“…Thus, the protection against the corrosive environment is lost [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Biotribology deals with the search for minimizing the effects of friction, which would involve reducing the wear of the surfaces involved in the friction of the elements and reducing the energy accompanying the process [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…For long-term implants, the service life of which should not exceed 15 years, cobalt alloys are applied [ 4 ]. Titanium and titanium alloys are most often used due to their best biocompatibility, and their service life may exceed 20 years [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 15 , 16 , 17 , 19 , 21 ]. The market of long-term implants is dominated by a commercially pure titanium alloy (Cp Ti) and a bi-phase (α + β) Ti–6Al–4V alloy known also as Grade 5 Titanium or Ti 6–4, which has excellent strength, a low modulus of elasticity, high corrosion resistance, good weldability, and is heat treatable [ 19 , 23 ].…”