WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 1Citation - Scopus: 1Influence 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, FatihRemovable 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: 6Citation - Scopus: 8Effect of the Combination of Organic Acid Solutions on Tinplate Corrosion(Elsevier, 2022) Yıldırım, Koray; Kızılkaya, Ali CanTinplate corrosion as a result of canned food is typically tested in industry by tinplate in synthetic media based on single organic acids. However, the combination of organic acids, which is present in applied conditions, is not previously investigated in terms of its effect on tinplate corrosion mechanism. In this manuscript, we combine structural characterization of tinplate surfaces with electrochemical measurements, to investigate the corrosion mechanism of tinplate under acetic acid-NaCl, citric acid-NaCl, and a combined acetic acid, citric acid and NaCl media. The results show that the combined acid media causes does not result in a pronounced formation of a protective passivation layer, in contrast to the single acid based media. Our findings demonstrate the combined effects of the organic acids in corrosive media has to be taken into account for tinplate corrosion, as they can alter the corrosion mechanism. Furthermore, we show that combination of organic acids can accelerate tinplate corrosion testing in packaging industry. Thus, our findings can contribute to the design of new aging media for tinplate corrosion testing.Article Citation - WoS: 20Citation - Scopus: 20Preliminary 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, FatihPoor 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.
