Analogue Modelling at the University at Albany, State University of New York

Youngdo Park, Jin-Han Ree & Win Means


There are 15 time-lapse movies on this page, which show the experimental deformation or post-deformation behaviour of octachloropropane (C3Cl8). Most of the experiments on this page were performed during December 1995, when JHR was visiting Albany. Feel free to download these movies for teaching. 
The order of the movies is such that the experimental strain rate decreases and temperature increases. 
Octachloropropane (OCP hereafter) is an organic material with hexagonal crystal symmetry. Polycrystalline OCP shows "similar(?)" microstructures to those found in quartzite. The material has been used to study various deformation processes by many workers (Win Means, Janos Urai, Mark Jessell, Jin-Han Ree, Paul Bons, Coen ten Brink, Cees Passchier), and is probably being used for the same purpose, even now somewhere on Earth (see Ree, 1994, J. Struct. Geol. vol. 16, 403-418 for details of the experiments). 
Nearly simple shearing grips (grips imposing simple shearing with a small "transpressional" component) were used for deformation, except in Movie 04 which shows a pure shear deformation experiment.

The horizontal dimension of the movies is ~1.5 mm.

Movie Format

Each experiment has been converted into QuickTime format.

The QuickTime versions can be viewed directly assuming you have an QuickTime viewer attached to your browser.


a) The movies display better if the monitor set to more than 256 colours.
b) Set the QuickTime player to display All Frames

In order to download any one of these movies, simply click on the icon to the right of the sample frames.

Movie 00: Cataclastic deformation

The sample is already deformed at beginning of movie. A sub-horizontal high strain rate zone or fault, marked by darker color, develops in the lower part of field. Some high strain rate zones, oriented at high angles to the shear direction, show the opposite sense of shear to that expected. Although concentrated shearing probably takes most of the bulk straining, some grains still deform internally. The last frame in the movie was taken with plane polarized light and shows the void spaces created during deformation.

In this movie  becomes  387k

Movie 01: Grain boundary opening

In the lower part of the pictures, grain boundary starts to open at expected orientation during sinistral shearing. Near the end of the movie, a feature which resembles transform fault connecting two openings (ridges) develops. Incipient opening at grain boundaries can also be seen at the end.

In this movie  becomes  314k

Movie 02: Formation of subgrains by rotational recrystallization

Irregular grain boundaries and small subgrains near grain boundaries form during deformation. The grain near the center of the field of the view, becomes sigmoidal in shape as deformation progresses. The grains in the top right of the movie show extensive grain boundary sliding as the experiment progesses. Also follow the behaviour of these two grains in the bottom right as the boundary between them switches from a grain boundary migration process to a grain boundary sliding process.

In this movie  becomes  861k

Movie 03: Post-deformational, microstructural changes of the sample of Movie 02

This movie records changes of microstructures after deformation. Can you tell the shear sense from the last pictures? How do the grains that survive until the end of movie originate? Observed at the same temperature as the preceding deformation.

In this movie  becomes  598k

Movie 04: Subgrain boundary formation and grain boundary migration

Sets of subgrain boundaries form within grains. The trace of these subgrain boundaries is subparallel to the c-axis orientation. Grain boundary migration can also be seen.

In this movie  becomes  234k

Movie 05: Post-deformational, microstructural changes of the sample of Movie 04

Grains change into nearly equilibrium texture of polycrystalline material in the end. There is also mysterious vertical lengthening (~5%) while the motor was off. Observed at the same temperature as the preceding deformation.

In this movie  becomes  458k

Movie 06: Contrast in deformation microstructures among domains of different strain rate

In this movie, a strain rate gradient in the vertical direction can be seen. Differences in microstructures such as foliation intensity, orientation and subgrain boundary density can be seen along the direction of strain rate gradient.

In this movie  becomes  629k

Movie 07: Post-deformational, microstructural changes of the sample of Movie 06

This movies shows how the rates of grain growth - strain energy driven or surface energy driven, are different for the strain rate domains of Movie 06. At the beginning, the process of grain growth in the high strain rate domain seems to be faster than that of low strain rate domain. However, with time, the rate of grain growth seems to be faster in the low strain rate domain, resulting in coarser grained texture in this domain in the end. Observed at the same temperature as the preceding deformation.

In this movie  becomes  1707k

Movie 08: Nearly identical rates of subgrain boundary migration across grain boundaries

This feature can be seen in the grains near the center of the field.

In this movie  becomes  166k

Movie 09: Development of high strain rate zones and formation of "ribbons" in the zones

Shearing is localized in the two zones near the top and bottom of the field. In these zones, subvertical alignment of subgrain boundaries can be seen. At the end, nearly single grain, at least in c-axis orientations, forms, which resembles ribbons.

In this movie  becomes  1961k

Movie 10: Subgrain boundary migration and grain size increase

Subgrain boundaries, oriented subvertically, migrate during deformation. Subhorizontal relative motions of markers within some grains can be seen, and this suggests that the slip planes of these grains are also subhorizontal or perpendicular to the subgrain boundaries. Since the traces of subgrain boundaries are subparallel to the c-axes, the observed motion of markers suggests slip on the basal planes.

In this movie  becomes  986k

Movie 11: Post-deformational, microstructural changes of the sample of Movie 10

In contrast to the previous examples, the microstructure of this sample remains about the same. This suggests that (1) microstructures with high subboundary density may be stable, or (2) microstructures in this sample do not change due to the starting low defect density acquired during low strain rate deformation. Observed at the same temperature as the preceding deformation.

In this movie  becomes  739k

Movie 12: Grain boundary migration during high temperature deformation

High mobility of grain boundaries can be seen in this experiment performed near the melting point. This experiment also shows reversal of shear-sense, obtained by reversing the drive motor. Microstructures do not seem to have good memory of old shear-sense.

In this movie  becomes  538k

Movie 13: Grain growth at zero strain rate

The numbers at the bottom right indicate time (hr:min:sec) after the first frame of the movie. Can you find an area which was swept twice by migrating grain boundaries?

In this movie  becomes  493k

Movie 14: Grain growth in a partial melt system

Some of the grain boundaries in this movie are wet by a melt, which is OCP saturated acetone. Similar grain growth to that of Movie 13 can be seen. Is the wetting angle changing during migration of boundaries? "Marker" particles that drift across the field of view are probably in melt film between sample and glass.

In this movie  becomes  213k

We thank our teacher, Professor W.D. Means for bringing us into this interesting field and his continuous support while we were at Albany. This work was supported by NSF grants to EAR-9017478 & EAR-9404872 to W.D. Means, and KOSEF grant 941-0400-003-2 to J.-H. Ree.

This page was assembled by Mark Jessell and any mistakes are probably his fault. 19/6/96