TY  - JOUR
A1  - Fernandez, Ricardo
A1  - Bruno, Giovanni
A1  - Garces, Gerardo
A1  - Nieto-Luis, H.
A1  - Gonzalez-Doncel, Gaspar
T1  - Fractional brownian motion of dislocations during creep deformation of metals
JF  - Materials science & engineering. A, Structural materials
N2  - The present work offers an explanation on how the long-range interaction of dislocations influences their movement, and therefore the strain, during creep of metals. It is proposed that collective motion of dislocations can be described as a fractional Brownian motion. This explains the noisy appearance of the creep strain signal as a function of time. Such signal is split into a deterministic and a stochastic part. These terms can be related to two kinds of dislocation motions: individual and collective, respectively. The description is consistent with the fractal nature of strain-induced dislocation structures predicated in previous works. Moreover, it encompasses the evolution of the strain rate during all stages of creep, including the tertiary one. Creep data from Al99.8% and Al3.85%Mg tested at different temperatures and stresses are used to validate the proposed ideas: it is found that different creep stages present different diffusion characters, and therefore different dislocation motion character.
KW  - Creep
KW  - Aluminum alloys
KW  - Dislocation motion
KW  - Diffusion
KW  - Fractal
KW  - structures
Y1  - 2020
U6  - https://doi.org/10.1016/j.msea.2020.140013
SN  - 0921-5093
SN  - 1873-4936
VL  - 796
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Fernandez, Ricardo
A1  - Gonzalez-Doncel, Gaspar
A1  - Garces, Gerardo
A1  - Bruno, Giovanni
T1  - Towards a comprehensive understanding of creep
BT  - microstructural dependence of the pre-exponential term in Al
JF  - Materials science & engineering. A, Structural materials: properties, microstructure and processing
N2  - We show that the equation proposed by Takeuchi and Argon to explain the creep behavior of Al-Mg solid solution can be used to describe also the creep behavior of pure aluminum. In this frame, it is possible to avoid the use of the classic pre-exponential fitting parameter in the power law equation to predict the minimum creep strain rate. The effect of the fractal arrangement of dislocations, developed at the mesoscale, must be considered to fully explain the experimental data. These ideas allow improving the recently introduced SSTC model, fully describing the primary and secondary creep regimes of aluminum alloys without the need for fitting. Creep data from commercially pure A199.8% and Al-Mg alloys tested at different temperatures and stresses are used to validate the proposed ideas.
KW  - creep
KW  - Aluminum alloys
KW  - dislocations
KW  - fractal
KW  - stress exponent
Y1  - 2020
U6  - https://doi.org/10.1016/j.msea.2020.139036
SN  - 0921-5093
SN  - 1873-4936
VL  - 776
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Fernandez, Gerardo
A1  - Laubrock, Jochen
A1  - Mandolesi, Pablo
A1  - Colombo, Oscar
A1  - Agamennoni, Osvaldo
T1  - Difficulties in predicting upcoming words
JF  - Journal of clinical and experimental neuropsychology
KW  - Eye movements
Y1  - 2014
U6  - https://doi.org/10.1080/13803395.2014.892060
SN  - 1380-3395
SN  - 1744-411X
VL  - 36
IS  - 3
SP  - 302
EP  - 316
PB  - Taylor & Francis Group
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Fernandez, Gerardo
A1  - Shalom, Diego E.
A1  - Kliegl, Reinhold
A1  - Sigman, Mariano
T1  - Eye movements during reading proverbs and regular sentences: the incoming word predictability effect
JF  - Language, cognition and neuroscience
KW  - eye movements
KW  - reading
KW  - proverbs
KW  - incoming word predictability effect
Y1  - 2014
U6  - https://doi.org/10.1080/01690965.2012.760745
SN  - 2327-3798
SN  - 2327-3801
VL  - 29
IS  - 3
SP  - 260
EP  - 273
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  -