Navegando por Assunto "Tribocorrosion"

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    Tribocorrosion studies on DLC films with silver nanoparticles for prosthesis applications
    (IOP Publishing) Radi, Polyana Alves; Vieira, Lúcia; Leite, Priscila Maria Sarmeiro Corrêa Marciano; Trava-Airoldi, Vladimir Jesus; Massi, Marcos; Reis, Danieli Aparecida Pereira
    Metals and their alloys are very important for orthopedic applications, and the basic requirements for a successful implant are chemical stability, mechanical behavior, and biocompatibility in body fluids and tissues. For prosthesis applications, the corrosion resistance of metals is one of the major prerequisites to avoid impairment of the material properties due to degradation. The combined action of corrosion and wear on the material is called tribocorrosion and DLC (Diamond-Like Carbon) films have been extensively studied to increase prosthesis biocompatibility and to protect from corrosion. Additionally, DLC coatings can prevent the prosthesis to release toxic elements due to plastic deformation and corrosion. This paper is about tribocorrosion studies on DLC and DLC-Ag (DLC containing silver nanoparticles) on Ti-6Al-4V substrates. These films were obtained by PECVD (Plasma Enhanced Chemical Vapor Deposition) using hexane as a precursor. The tribocorrosion behavior of uncoated and coated samples was investigated in the reciprocating mode in Ringer's lactate solution. From the polarization test results, the protective efficiency of the film was calculated. Silver nanoparticles improved the corrosion resistance of the films. The protective efficiency was 15 and 19% for DLC and DLC-Ag films, respectively.
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    Wear Rate, Tribo-Corrosion, and Plastic Deformation Values of Co-Cr-Mo Alloy in Ringer Lactate Solution
    (MDPI) Silva, Raimundo Nonato Alves; Neto, Rui; Vieira, Angela Aparecida; Leite, Priscila Maria Sarmeiro Corrêa Marciano; Radi, Polyana Alves; Silveira, Carolina Hahn da; Santos, Marcos Dantas dos; Viana, Filomena; Vieira, Lúcia
    This study investigates the tribocorrosion performance of a cast Co-Cr-Mo alloy prepared using casting and electromagnetic stirring (EMS) at specific frequencies. The tribocorrosion behaviour of the alloy was evaluated when exposed to Ringer’s lactate solution to optimize the EMS parameters and improve its properties. The research focuses on biomedical implant applications and explores how EMS affects alloy wear and corrosion resistance. As did the friction coefficient and wear volume, the wear rate of samples produced with EMS frequencies of 75 Hz and 150 Hz decreased. These improvements are attributed to the ability of EMS to refine grain size and homogenize the microstructure, thereby increasing the resistance to tribocorrosion. Techniques such as scanning electron microscopy (SEM) and profilometry were used for surface and wear analysis, while mechanical properties were evaluated through instrumented indentation tests. The findings confirm that EMS improves the alloy’s durability and tribocorrosion resistance, making it highly suitable for demanding biomedical applications such as joint replacements. This highlights the importance of advanced manufacturing techniques in optimizing biomedical alloys for simulated body conditions.