scholarly journals Magmatic Focusing to Mid-Ocean Ridges: The Role of Grain-Size Variability and Non-Newtonian Viscosity

2017 ◽  
Vol 18 (12) ◽  
pp. 4342-4355 ◽  
Author(s):  
Andrew J. Turner ◽  
Richard F. Katz ◽  
Mark D. Behn ◽  
Tobias Keller
Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1019 ◽  
Author(s):  
Angella ◽  
Donnini ◽  
Ripamonti ◽  
Górny ◽  
Zanardi

Tensile testing on ductile iron GJS 400 with different microstructures produced through four different cooling rates was performed in order to investigate the relevance of the microstructure’s parameters on its plastic behaviour. Tensile flow curve modelling was carried out with the Follansbee and Estrin-Kocks-Mecking approach that allowed for an explicit correlation between plastic behaviour and some microstructure parameters. In the model, the ferritic grain size and volume fraction of pearlite and ferrite gathered in the first part of this investigation were used as inputs, while other parameters, like nodule count and interlamellar spacing in pearlite, were neglected. The model matched very well with the experimental flow curves at high strains, while some mismatch was found only at small strains, which was ascribed to the decohesion between the graphite nodules and the ferritic matrix that occurred just after yielding. It can be concluded that the plastic behaviour of GJS 400 depends mainly on the ferritic grain size and pearlitic volume fraction, and other microstructure parameters can be neglected, primarily because of their high nodularity and few defects.


2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Christoph Hauer ◽  
Günther Unfer ◽  
Patrick Holzapfel ◽  
Marlene Haimann ◽  
Helmut Habersack

1994 ◽  
Vol 77 (7) ◽  
pp. 1928-1938 ◽  
Author(s):  
Desiderio Kovar ◽  
Michael J. Readey

2021 ◽  
Vol 30 (2) ◽  
pp. 215-225
Author(s):  
Marthe Kretzschmar

Knowledge of the materiality of stone during the Enlightenment expanded following the exploration of mineralogical structure, to alter ideas about taxonomy and challenge the role of rocks in the history of the earth. Close studies of the material of marble sculpture generated expertise on grain size, surface varieties and stone deposits. This mode of reception became intertwined with contemporary controversies about the age of the earth. This article focuses on both French sculpture and geological discourses of the eighteenth century to reveal an international and interdisciplinary network centring on protagonists such as Denis Diderot, Paul-Henri Thiry d’Holbach and Étienne-Maurice Falconet; through these figures, debates can be connected concerning both geology and art theory. Within these contexts, the article discusses the translation processes between these artistic and geological interests.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 369 ◽  
Author(s):  
Mo Ji ◽  
Claire Davis ◽  
Martin Strangwood

This paper discusses the role of grain size distribution on the recrystallisation rates and Avrami values for a Fe-30 wt. % Ni steel, which was used as a model alloy retaining an austenitic structure to room temperature. Cold deformation was used to provide uniform macroscopic strain distributions (strains of 0.2 and 0.3), followed by recrystallisation during annealing at 850–950 °C. It was shown that the Avrami parameter was directly related to the grain size distribution, with a lower Avrami exponent being seen for a larger average and wider grain size distribution. A method to predict the Avrami exponent from the grain size distribution was proposed. In situ heating in an SEM with EBSD showed the recrystallisation kinetics to be affected by differences in stored energy and nucleation in the different grain sizes supporting the proposed relationship.


Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1282 ◽  
Author(s):  
Giuliano Angella ◽  
Dario Ripamonti ◽  
Marcin Górny ◽  
Stefano Masaggia ◽  
Franco Zanardi

A series of samples made of ductile iron GJS 400 was cast with different cooling rates, and their microstructural features were investigated. Quantitative metallography analyses compliant with ASTM E2567-16a and ASTM E112-13 standards were performed in order to describe graphite nodules and ferritic grains. The occurrence of pearlite was associated to segregations described through Energy Dispersive X-ray Spectroscopy (EDS) analyses. Results were related to cooling rates, which were simulated through MAGMASOFT software. This microstructural characterization, which provides the basis for the description and modeling of the tensile properties of GJS 400 alloy, subject of a second part of this investigation, highlights that higher cooling rates refines microstructural features, such as graphite nodule count and average ferritic grain size.


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