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Ara es mostren els items 11-30 de 185

    • Berkovich nanoindentation and deformation mechanisms in a hardmetal binder-like cobalt alloy 

      Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Tarragó Cifre, Jose María; Zivcec, Maria; Broeckmann, C.; Llanes Pitarch, Luis Miguel (2014-11)
      Article
      Accés restringit per política de l'editorial
      A cobalt-base solid solution is the most used binder for hardmetals (WC–Co cemented carbides) in a wide range of industrial applications. In the composite material such cobalt alloy is surrounded by hard carbides grains; ...

    • Caracterización mecánica a escala picométrica de YBa1.75Sr0.25Cu3O7-d monocristalino mediante la técnica de autoflujo 

      Roa Rovira, Joan Josep; Dias, F.T.; Vieira, V.N.; Oncins, Gerard; Díaz, Jordi; Schaf, J.; Capdevila, X.G.; Segarra, M. (Universidad de Cantabria, 2009)
      Comunicació de congrés
      Accés obert
      Se implementa un método para indentar superficies rígidas a niveles nanométricos utilizando un microscopio de fuerzas atómicas (Atomic Force Microscopy-AFM), empleando el modo de espectroscopia de fuerzas (Force ...

    • Carbon addition effects on microstructure and small-scale hardness for Ti(C,N)-FeNi cermets 

      Besharatloo, H.; Nicolás Morillas, Maria de; Wheeler, J.M.; Mateo García, Antonio Manuel; Ferrari, Begoña; Gordo Odériz, Elena; Llanes Pitarch, Luis Miguel; Roa Rovira, Joan Josep (2019-12-01)
      Article
      Accés obert
      The current study investigates the influence of carbon addition on the microstructural and micromechanical properties of Ti(C,N)-FeNi cermets with different ceramic/metal phase ratios. Evaluation of small-scale hardness ...

    • Characterization of interfaces between TiCN and iron-base binders 

      Alvaredo, P; Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Llanes Pitarch, Luis Miguel; Gordo Odériz, Elena (2017-02-01)
      Article
      Accés obert
      This work includes a study of the interface between matrix and reinforcement in Fe-Ti(C,N) systems. A study of wettability and solubility between metal and ceramic phases is first performed. It combines wetting experiments ...

    • Characterization study of an oxide film layer produced under CO2/steam atmospheres on two different maraging steel grades 

      Cerra Flórez, Mauro Andrés; Fargas Ribas, Gemma; Roa Rovira, Joan Josep (Multidisciplinary Digital Publishing Institute (MDPI), 2021-05-01)
      Article
      Accés obert
      Currently, surface treatments lead to inducing a superficial layer of several nanometers up to micrometer, which in some cases can be protective. In this experimental work, an oxide layer was generated under different ...

    • Chemical and nanoindentation study of diffusion during sintering of 12Ce-ZrO2/3Y-ZrO2 powder layers 

      Roa Rovira, Joan Josep; Turón Viñas, Miquel; Tovar Vargas, Daniela; Ledesma, J.; Anglada Gomila, Marcos Juan (2018-02-01)
      Article
      Accés restringit per política de l'editorial
      Tetragonal zirconia polycrystals doped with 3% mol of yttria (3Y-ZrO2) exhibit excellent mechanical properties and biocompatibility. However, under humid environments, their surface structural integrity is degraded by aging ...

    • Chemical introduced disorder effects on the critical current density and pinning mechanisms of YBa2-XSrXCu3O7-¿ 

      Flores, R. L.; Vieira, Valdemar das Neves; Teixeira Dias, Fábio; Pureur, P; Schaf, Jacob; Hneda, M; Roa Rovira, Joan Josep (2016)
      Article
      Accés obert
      We report on isotherm ( T = 77.5 K) DC magnetization hysteresis loops of a series of YBa 2 -x Sr x Cu 3 O 7 - ¿ (x = 0, 0.02, 0.1, 0.25 and 0.37) single crystals with the purpose of studying the influence of chemically ...

    • Chemical milling effect on the low cycle fatigue properties of cast Ti-6Al-2Sn-4Zr-2Mo alloy 

      Sefer, Birhan; Gaddam, Raghuveer; Roa Rovira, Joan Josep; Mateo García, Antonio Manuel; Antti, Marta-lena; Pederson, Robert (2016-11-01)
      Article
      Accés obert
      The current research work presents the chemical milling effect on the low cycle fatigue properties of cast Ti–6Al–2Sn–4Zr–2Mo alloy. Chemical milling treatment is one of the final steps in manufacturing titanium alloy ...

    • Chemical segregation in a 12Ce-ZrO2/3Y-ZrO2 ceramic composite 

      Roa Rovira, Joan Josep; Aboulfadl, Hisham; Barrirero, Jenifer; Turón Viñas, Miquel; Mücklich, Frank; Anglada Gomila, Marcos Juan (2017-10-01)
      Article
      Accés restringit per política de l'editorial
      In restorative dentistry, 3Y-ZrO2 ceramics are widely accepted for fabricating dental crowns, bridges and implants due to their good biocompatibility, excellent mechanical properties and high aesthetics potential. However, ...

    • Comparison between the magnetic irreversibility and zero resistance of high-quality melt-processed ybacuo superconductors 

      Teixeira Dias, Fábio; Vieira, Valdemar das Neves; Wolff-Fabris, Frederik; Kampert, Erik; Hneda, M; Schaf, Jacob; Farinela, G; Paiva Gouvêa, Cristol de; Roa Rovira, Joan Josep (2016)
      Article
      Accés obert
      This paper portrays a detailed study of the magnetic irreversibility limit Tirr (H) and of the zero resistance point Tc0 (H) of three different top-seeding melt-textured YBa2Cu3O7-d superconducting samples, with well-aligned ...

    • Comportamento irreversível da magnetizaçao do YBaCuO texturizado 

      Mendoza, R. M. N.; Vieira, Valdemar das Neves; Silva, D. L. da; Roa Rovira, Joan Josep; Wolff-Fabris, Frederik; Teixeira Dias, Fábio (2014)
      Comunicació de congrés
      Accés obert

    • Comportamiento mecánico de materiales masivos supercondcutores de segunda generación en función de la temperatura 

      Konstantopoulou, K.; Pastor, J.Y.; Roa Rovira, Joan Josep; Segarra, M. (2010-07-01)
      Article
      Accés obert
      En este trabajo se han analizado dos materiales masivos superconductores de base YBaCuO, con el objetivo de estudiar la influencia del método de procesado (método Bridgman y método Top-Seeding Melt Growth) y de la temperatura ...

    • Contact damage and fracture micromechanism of multilayered TiN/CrN coatings at micro- and nano-length scales 

      Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Martínez, R; Ramírez Sandoval, Giselle; Tarragó, Josep Maria; Rodríguez, R; Llanes Pitarch, Luis Miguel (2014)
      Article
      Accés restringit per política de l'editorial
      In this study, systematic nanomechanical andmicromechanical studies have been conducted in threemultilayer TiN/CrN systems with different bilayer periods (8, 19 and 25 nm). Additionally, experimental work has been ...

    • Contact fatigue behavior of a-Al2O3-Ti(C,N) CVD coated WC-Co under dry and wet conditions 

      Sosa, Amadeo Daniel; Collado Ciprés, Verónica; García, José; Escalada, Lisandro; Roa Rovira, Joan Josep; Soldera, Flavio; Brühl, Elisabeth; Llanes Pitarch, Luis Miguel; Simison, Sílvia Noemí (2021-02-01)
      Article
      Accés obert
      The response to cycling contact fatigue load of a WC-6%Co carbide coated with a Ti(C,N)/a-Al2O3 CVD multilayer was investigated in dry and wet conditions. Imprints in dry conditions were characterized by small thin cracks ...

    • Contact fatigue behaviour of CVD coated cemented carbides in dry and wet conditions 

      Collado Ciprés, Verónica; Dalibon Bähler, Eugenia Laura; Escalada, Lisandro; Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Soldera, Flavio; Brühl, Sonia P.; Simison, Sílvia Noemí; Llanes Pitarch, Luis Miguel; Sosa, Amadeo Daniel (2022-03-15)
      Article
      Accés obert
      Cycling contact fatigue indentation tests in dry and wet conditions were conducted in cemented carbides CVD-coated with Ti(C,N)/a-Al2O3 and Zr(C,N)/a-Al2O3 systems. In dry contact experiments, all imprints presented a ...

    • Correlation between electrical and mechanical properties in La1-XSrXGa1-YMgYO3-¿ ceramics used as electrolytes for solid oxide fuel cells 

      Morales Comas, Miguel; Roa Rovira, Joan Josep; Pérez Falcón, José Manuel; Moure Arroyo, Alberto; Tartaj, Jesus; Espiell Álvarez, Ferran; Segarra Rubi, Merce (2014)
      Article
      Accés restringit per política de l'editorial
      The relation between the electrical and the mechanical properties in Sr and Mg doped LaGaO3 ceramics, which can be used as electrolyte for solid oxide fuel cells, was investigated in terms of hardness and ionic conductivity. ...

    • Correlation between electrical and mechanical properties in La1-xSrxGa1-yMgyO3-d ceramics used as electrolytes for solid oxide fuel cells 

      Morales Comas, Miguel; Roa Rovira, Joan Josep; Pérez Falcón, José Manuel; Moure Arroyo, Alberto; Tartaj, Jesus; Espiell Álvarez, Ferran; Segarra Rubi, Merce (2014)
      Article
      Accés restringit per política de l'editorial
      The relation between the electrical and the mechanical properties in Sr and Mg doped LaGaO3 ceramics, which can be used as electrolyte for solid oxide fuel cells, was investigated in terms of hardness and ionic conductivity. ...

    • Correlation between microstructure and mechanical properties before and after reversion of metastable austenitic stainless steels 

      Fargas Ribas, Gemma; Zapata, Ana; Roa Rovira, Joan Josep; Sapezanskaia, Ina; Mateo García, Antonio Manuel (2015)
      Article
      Accés obert
      Reversion treatments are a way to improve the mechanical response of metastable austenitic stainless steels by means of grain refinement. To effectively apply those treatments, the steel must be previously deformed to ...

    • Corrosion damage in WC-Co cemented carbides: residual strength assessment and 3D FIB-FESEM tomography characterisation 

      Tarragó Cifre, Jose María; Fargas Ribas, Gemma; Jiménez Piqué, Emilio; Felip, Alba; Isern, Lluis; Coureaux Mustelier, David; Roa Rovira, Joan Josep; Al-Dawery, Ihsan; Fair, Jonathan; Llanes Pitarch, Luis Miguel (2014-12-01)
      Article
      Accés restringit per política de l'editorial
      The effect of corrosion damage on cemented carbides was investigated. The study included residual strength assessment and detailed fractographic inspection of corroded specimens as well as detailed 3D FIB-FESEM tomography ...

    • Corrosion damage in WC-Co cemented carbides: Residual strength assessment and 3D FIB-FESEM tomography characterization 

      Tarragó Cifre, Jose María; Fargas Ribas, Gemma; Jiménez Piqué, Emilio; Felip, Alba; Isern, Lluis; Coureaux Mustelier, David; Al-Dawery, Ihsan; Roa Rovira, Joan Josep; Fair, Jonathan; Llanes Pitarch, Luis Miguel (2014)
      Text en actes de congrés
      Accés obert
      The effect of corrosion damage on cemented carbides was investigated. The study included residual strength assessment and detailed fractographic inspection of corroded specimens as well as detailed 3D FIB-FESEM tomography ...