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.