Estudo da resistência à fadiga da liga Ti-6Al-4V com superfície modificada por tratamento químico
Abstract
Chemical surface treatments (CST) in cementless and endosseous
implants are used to increase the implant-bone contact area, reducing the period
of osseointegration and favouring bonding ability between implants and bone.
However, surface modifications can affect the fatigue strength of these materials,
especially the fatigue crack nucleation. For these reasons, this work evaluated the
influence of the surface modification using acid etching, combined with alkaline
treatment on the fatigue strength of Ti-6Al-4V ELI alloy. The topography
developed by chemical surface treatments was examined by scanning electron
microscopy (SEM) and confocal laser scanning microscopy (CLSM). Increased
roughness and the effective surface area were investigated and compared with the
Ti-6Al-4V samples without modification. Surface composition was analyzed by
energy dispersive X-ray spectroscopy (EDS). Axial fatigue resistances of polished
and modified surfaces were determined by stepwise load increase tests and
staircase test method. Finally, SEM was employed to examine the fracture surface
of the tested specimens. According to the results, it was observed a similar fatigue
behavior of the chemically treated Ti-6Al-4V alloy compared to the samples without treatment.