Theoretical analysis to interpret projected image data from in-situ 3-dimensional equiaxed nucleation and growth

R. P. Mooney, S. McFadden

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In-situ observation of crystal growth in transparent media allows us to observe solidification phase change in real-time. These systems are analogous to opaque systems such as metals. The interpretation of transient 2-dimensional area projections from 3-dimensional phase change phenomena occurring in a bulky sample is problematic due to uncertainty of impingement and hidden nucleation events; in stereology this problem is known as over-projection. This manuscript describes and demonstrates a continuous model for nucleation and growth using the well-established Johnson-Mehl-Avrami-Kolmogorov model, and provides a method to relate 3-dimensional volumetric data (nucleation events, volume fraction) to observed data in a 2-dimensional projection (nucleation count, area fraction). A parametric analysis is performed; the projection phenomenon is shown to be significant in cases where nucleation is occurring continuously with a relatively large variance. In general, area fraction on a projection plane will overestimate the volume fraction within the sample and the nuclei count recorded on the projection plane will underestimate the number of real nucleation events. The statistical framework given in this manuscript provides a methodology to deal with the differences between the observed (projected) data and the real (volumetric) measures.
LanguageEnglish
Pages43-50
JournalJournal of Crystal Growth
Volume480
Early online date4 Oct 2017
DOIs
Publication statusPublished - 15 Dec 2017

Fingerprint

nucleation
solidification
in situ
analysis
crystal
methodology
metal

Keywords

  • A1. Nucleation
  • A1. Optical Microscopy
  • A1. Solidification
  • A2. Microgravity conditions
  • B1. Alloys
  • A1. Computer Simulation

Cite this

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title = "Theoretical analysis to interpret projected image data from in-situ 3-dimensional equiaxed nucleation and growth",
abstract = "In-situ observation of crystal growth in transparent media allows us to observe solidification phase change in real-time. These systems are analogous to opaque systems such as metals. The interpretation of transient 2-dimensional area projections from 3-dimensional phase change phenomena occurring in a bulky sample is problematic due to uncertainty of impingement and hidden nucleation events; in stereology this problem is known as over-projection. This manuscript describes and demonstrates a continuous model for nucleation and growth using the well-established Johnson-Mehl-Avrami-Kolmogorov model, and provides a method to relate 3-dimensional volumetric data (nucleation events, volume fraction) to observed data in a 2-dimensional projection (nucleation count, area fraction). A parametric analysis is performed; the projection phenomenon is shown to be significant in cases where nucleation is occurring continuously with a relatively large variance. In general, area fraction on a projection plane will overestimate the volume fraction within the sample and the nuclei count recorded on the projection plane will underestimate the number of real nucleation events. The statistical framework given in this manuscript provides a methodology to deal with the differences between the observed (projected) data and the real (volumetric) measures.",
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author = "Mooney, {R. P.} and S. McFadden",
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Theoretical analysis to interpret projected image data from in-situ 3-dimensional equiaxed nucleation and growth. / Mooney, R. P.; McFadden, S.

Vol. 480, 15.12.2017, p. 43-50.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Theoretical analysis to interpret projected image data from in-situ 3-dimensional equiaxed nucleation and growth

AU - Mooney, R. P.

AU - McFadden, S.

PY - 2017/12/15

Y1 - 2017/12/15

N2 - In-situ observation of crystal growth in transparent media allows us to observe solidification phase change in real-time. These systems are analogous to opaque systems such as metals. The interpretation of transient 2-dimensional area projections from 3-dimensional phase change phenomena occurring in a bulky sample is problematic due to uncertainty of impingement and hidden nucleation events; in stereology this problem is known as over-projection. This manuscript describes and demonstrates a continuous model for nucleation and growth using the well-established Johnson-Mehl-Avrami-Kolmogorov model, and provides a method to relate 3-dimensional volumetric data (nucleation events, volume fraction) to observed data in a 2-dimensional projection (nucleation count, area fraction). A parametric analysis is performed; the projection phenomenon is shown to be significant in cases where nucleation is occurring continuously with a relatively large variance. In general, area fraction on a projection plane will overestimate the volume fraction within the sample and the nuclei count recorded on the projection plane will underestimate the number of real nucleation events. The statistical framework given in this manuscript provides a methodology to deal with the differences between the observed (projected) data and the real (volumetric) measures.

AB - In-situ observation of crystal growth in transparent media allows us to observe solidification phase change in real-time. These systems are analogous to opaque systems such as metals. The interpretation of transient 2-dimensional area projections from 3-dimensional phase change phenomena occurring in a bulky sample is problematic due to uncertainty of impingement and hidden nucleation events; in stereology this problem is known as over-projection. This manuscript describes and demonstrates a continuous model for nucleation and growth using the well-established Johnson-Mehl-Avrami-Kolmogorov model, and provides a method to relate 3-dimensional volumetric data (nucleation events, volume fraction) to observed data in a 2-dimensional projection (nucleation count, area fraction). A parametric analysis is performed; the projection phenomenon is shown to be significant in cases where nucleation is occurring continuously with a relatively large variance. In general, area fraction on a projection plane will overestimate the volume fraction within the sample and the nuclei count recorded on the projection plane will underestimate the number of real nucleation events. The statistical framework given in this manuscript provides a methodology to deal with the differences between the observed (projected) data and the real (volumetric) measures.

KW - A1. Nucleation

KW - A1. Optical Microscopy

KW - A1. Solidification

KW - A2. Microgravity conditions

KW - B1. Alloys

KW - A1. Computer Simulation

U2 - 10.1016/j.jcrysgro.2017.10.002

DO - 10.1016/j.jcrysgro.2017.10.002

M3 - Article

VL - 480

SP - 43

EP - 50

ER -