1,721,064 research outputs found
Effect of the Sc and Zr addition on the microstructure and fatigue properties of AA6106 produced by equa-channel-angular-pressing
Full text linkMicrostructure kinetics of fine precipitates after solution treatments in a thixo-cast AZ91 (Mg-Al-Zn) alloy,
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Influence of severe plastic deformation on secondary phase precipitation in a 6082 Al-Mg-Si alloy
No full textThe role of severe plastic deformation on the second-phase stability in a 6082 Al-Mg-Si alloy was studied using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) techniques.
The alloy was fully annealed prior to undergoing up to six equal channel angular pressing (ECAP) passes using route C. The Orowan strengthening mechanism was calculated on the basis of TEM inspections for the two hardening second-phase precipitates: Mg2Si and Si. The former had a major tendency to be cut and fragmented by dislocations, while in the latter, a dissolution process was induced by severe plastic deformation. Accordingly, the second-phase Si particles became progressively less effective with increasing deformation (i.e., additional ECAP passes). The increase in hardness with the ECAP passes was mostly due to the grain refining mechanism and to dislocation tangles within the newly formed grains. The expected, though if limited, contribution of second-phase hardening was prevalently accounted for by the Mg2Si particles
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Characterisation of a 6082 aluminum alloy after thixoforming
No full textcomparison of aging treatments on bars and components
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Creep behaviour of INCOLOY alloy 617
No full textThe microstructural features of INCOLOY
alloy 617 in the solution annealed condition and after longterm
creep tests at 700 and 800 C were characterized and
correlated with hardness and creep strength. Major precipitates
included (Cr,Mo,Fe)23C6 carbides and the
d-Ni3Mo phase. M6C and MC carbides were also detected
within the austenitic grains. However, minor precipitates
particularly c¢-Ni3(Al,Ti) was found to play an important
role. At different exposure temperatures, the microstructural
features of the Ni–22Cr–12Co–9Mo alloy changed
compared with the as-received condition. The presence of
discontinuously precipitated (Cr,Mo,Fe)23C6 carbides and
their coarsening until the formation of an intergranular film
morphology could be responsible both for a reduction in
rupture strength and for enhanced intergranular embrittlement.
The fraction and morphology of the c¢-phase, precipitated
during exposure to high temperature, also
changed after 700 or 800 C exposure. At the latter test
temperature, a lower volume fraction of coarsened and
more cubic c¢ precipitates were observed. These microstructural
modifications, together with the presence of the
d-phase, detected only in specimens exposed to 700 C,
were clearly responsible for the substantially good creep
response observed at 700 C, compared with that found at
800 C
Esperienze di produzione mediante tecnica Equal Channel Angular Pressing e proprietà di leghe di alluminio massive a struttura ultrafine
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