Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

20222

Settings

Access Right: Embargoed AccessAuthor: search.filters.author.Alves, Alexandra C.

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Influence of Processing Method of Cocrmo Dental Alloy on the Corrosion Behavior in Artificial Saliva
    (Wiley, 2022) Pontes, Joana R.; Pinto, Ana M. P.; Ariza, Edith; Alves, Alexandra C.; Toptan, Fatih
    Removable or fixed dental frameworks are usually made of CoCr alloys. The CoCr dental alloys are produced traditionally by lost-wax casting. However, alternative processing routes, such as hot-pressing, are being studied for dental applications. The purpose of the present work was to assess the corrosion resistance of CoCrMo dental alloy produced by conventional lost-wax casting and hot-pressing. The corrosion behavior was studied in artificial saliva at 37°C by potentiodynamic polarisation tests. Immersion tests were performed to evaluate the growth of the passive film where electrochemical impedance spectroscopy was used at different immersion periods. Results showed slightly better corrosion resistance in terms of ipass for CoCrMo samples obtained by hot-pressing. On the other hand, the immersion tests showed a more stable and thicker passive film formed on hot-pressed CoCrMo dental alloy, pointing out that hot-pressing may be considered a promising technique to produce CoCrMo dental structures.
  • Article
    Citation - WoS: 20
    Citation - Scopus: 20
    Preliminary Tribo-Electrochemical and Biological Responses of the Ti-Tib In-Situ Composites Intended for Load-Bearing Biomedical Implants
    (Elsevier, 2022) Sousa, Lia; Toptan, Fatih; Alves, Alexandra C.; Costa, N. A.; Gemini Piperni, Sara; Rossi, Andre Linhares; Ribeiro, Ana R.; Simöes, Sönia; Toptan, Fatih
    Poor tribocorrosion resistance of Ti and its alloys remains as a concern for load-bearing biomedical implants. Despite being an effective method to improve tribocorrosion resistance, titanium matrix composites (TMCs) have yet to be used in this type of applications. In-situ TiB (titanium boride) and TiC (titanium carbide) reinforcement phases have been considered as one of the best options to produce TMCs once these phases present high compatibility and strong interfacial bonding with Ti. Although the effect of these phases on the mechanical properties of Ti has been thoroughly researched in the last years, their effect on corrosion, tribocorrosion and biocompatibility of Ti is yet to be fully understood. In this work, in-situ Ti-TiB-TiCx composites obtained by reactive hot pressing showed identical corrosion response compared to the unreinforced Ti but displayed improved tribocorrosion behaviour. Under 0.5 N load, composites presented as average a reduction of 51% in wear volume loss and under 10 N the reduction was up to 93%. Early biological tests showed promising results, as composites were biocompatible and induced osteoblasts spreading and possibly proliferation most probably due to composite chemistry and surface hardness.