Experimental solidification of anhydrous latitic and trachytic melts at different cooling rates: The role of nucleation kinetics

2008 ◽  
Vol 253 (3-4) ◽  
pp. 91-101 ◽  
Author(s):  
Gianluca Iezzi ◽  
Silvio Mollo ◽  
Guido Ventura ◽  
Andrea Cavallo ◽  
Claudia Romano
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.


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.


1985 ◽  
Vol 57 ◽  
Author(s):  
D. R. Uhlmann ◽  
M. C. Weinberg

AbstractThe role of nucleation kinetics in affecting glass formation behavior is discussed. Also considered are measurements of homogeneous crystal nucleation in a variety of liquids. For a number of oxide glass-forming liquids, available data indicate pre-exponential factors which are larger than those predicted from classical nucleation theory by factors of 1017 to 1049. Possible sources of this discrepancy are discussed.


2016 ◽  
Vol 145 (21) ◽  
pp. 211920 ◽  
Author(s):  
Prabhat K. Gupta ◽  
Daniel R. Cassar ◽  
Edgar D. Zanotto

1986 ◽  
Vol 74 ◽  
Author(s):  
J. E. Greene ◽  
A. Rockett ◽  
J.-E. Sundgren

AbstractLow-energy (often < 100 eV) ion bombardment during thin film deposition is commonly used in such diverse application areas as microelectronics, optical coatings. magnetic recording layers. and hard wear resistant coatings to modify the microstructure and microchemistry of films deposited by a variety of techniques (e.g. sputtering, primary ion deposition, plasma-assisted CVD, and accelerated-beam MBE). Ion irradiation has been shown to affect every phase of deposition including nucleation and growth kinetics, crystal structure and phase stability, the average grain size and degree of preferred orientation of polycrystalline films, the epitaxial temperature of single-crystal films, defect concentrations, elemental incorporation probabilities, surface segregation, and, hence, film properties. As discussed in this brief review, a detailed understanding of many of these processes is beginning to emerge. Effects such as trapping, preferential sputtering, enhanced diffusion, and collisional mixing have been used to interpret and, in some cases, model experimental results. Nevertheless, there are still large gaps in our knowledge of the role of ion bombardment on fundamental processes such as nucleation kinetics.


2012 ◽  
Vol 125 (6) ◽  
pp. 4233-4242 ◽  
Author(s):  
Stefano Piccarolo ◽  
Anesh Manjaly Poulose ◽  
Alessandro Luzio

CrystEngComm ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Yufeng Quan ◽  
Yang Yang ◽  
Shijie Xu ◽  
Peipei Zhu ◽  
Shiyuan Liu ◽  
...  

Considering the role of piperazine in the TEDA–MTBE system, we investigate how to control the crystal size distribution.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Ting Wen ◽  
Hairong Wang ◽  
Chunrong Li ◽  
Jikun Xu ◽  
Chuntao Zhang

In order to investigate the nucleation behavior of arbidol hydrochloride monohydrate (AHM) in the aqueous THF (Tetrahydrofuran) solutions, metastable zone width (MSZW) was experimentally determined via the polythermal method, and...


Sign in / Sign up

Export Citation Format

Share Document