Navegando por Palavras-chave "Creep"

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    Creep behavior evaluation and characterization of SiC film with Cr interlayer deposited by HiPIMS in Ti-6Al-4V alloy
    (Elsevier Science Sa, 2017) Sugahara, Tarcila [UNIFESP]; Martins, Gislene Valdete; Montoro, Fabiano Emmanuel; Merij Neto, Abrao [UNIFESP]; Massi, Marcos [UNIFESP]; da Silva Sobrinho, Argemiro Soares; Pereira Reis, Danieli Aparecida [UNIFESP]
    This paper presents a study about creep behavior of SiC thin films with Cr interlayer deposited by High Power Impulse Magnetron Sputtering (HiPIMS) on Ti-6Al-4V alloys with Widmanstatten microstructure. After SiC/Cr film depositions, a microstructural characterization was performed using Scratching Test, Scanning Electron Microscopy (SEM), Scanning and Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) techniques. Scratching tests showed that the film was well adhered to the substrate, which proves that the Cr interlayer is closely related to the strength of adhesion between SiC film and the substrate. The SiC film surface morphology has columnar shape according to STEM images. Creep test results were compared with earlier Ti-6Al-4V Widmanstatten microstructure studies, and they showed an increased lifetime for the Ti-6Al-4V Widmanstatten microstructure with SiC/Cr film, which indicates a higher creep resistance than the specimen without the SiC/Cr film. The SiC/Cr film deposited by HiPIMS improved the creep behavior of the Ti-6Al-4V Widmanstatten microstructure. (C) 2016 Elsevier B.V. All rights reserved.
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    Estudo das alterações mecânicas e microestruturais na liga Ti-6Al-4V submetido a implantação iônica por imersão em plasma (3IP-N)
    (Universidade Federal de São Paulo (UNIFESP), 2019-05-27) Goncalves, Fabricia Assis Resende [UNIFESP]; Reis, Danieli Aparecida Pereira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    In this work, we intended to continue the research has already begun in the studies of creep of the Ti-6Al-4V alloy. The objective of this work was the study of Ionic Implantation by Plasma Immersion (3IP-N) in corrosion and creep behavior of Ti-6Al-4V alloy. Materials with appropriate behavior at high temperatures and aggressive environments have become a scientific, technological and economically viable necessity nowadays. The Ti-6Al-4V alloy, studied in this work, was obtained in the annealed condition, after the machining of the samples in the desired dimensions, they were submitted to the surface alteration process, via Immersion Ion Implantation to Plasma (3IP-N), had using nitrogen gas and auxiliary heating. The 3IP-N treatment was performed at two different implantation times for all samples (1 and 2 h) and at different exposure temperatures (700, 800 and 900 °C). The purpose of the treatment was to achieve changes in the surface properties of the alloy, such as the formation of a surface layer of titanium nitrides (TiN and Ti2N) and to obtain improvements in the properties of the material. For the characterization of the samples, the following techniques were used: conventional X-ray diffractometry (XRD) and Grazing Incidence X-ray Diffraction (GIXRD); Glow Discharge Optical Emission (GDOES), optical profilometry, nanoindentation, microindentation, wear, potentiodynamic polarization, optical microscopy (MO) and creep test. With a treatment application a layer was applied on the surface of the samples that positively influenced the mechanical properties of the alloy, increasing the resistance to wear, presenting a tendency favorable to the corrosion resistance, increasing the creep life in a period of 8 That greater for the 3IP-N condition at 900 ° C for 1 h when compared to untreated sample. The mechanical responses obtained confirm the efficiency of the nitrided layer promoted by the 3IP-N treatment in the Ti-6Al-4V alloy.