Bright light on ancient materials
Art and science collaborate to explore the past with X-rays at Argonne National
Laboratory
(Download printable, PDF version.)
ARGONNE, Ill. (March 30, 2007) — When a prestigious art institute owns
a precious, ancient artifact and wants to know more about its origin, special
non-destructive tools are needed.
Scientists at the U.S. Department of Energy's Argonne National Laboratory
are collaborating with colleagues at the Art
Institute of Chicago and Northwestern
University to investigate the casting technology and the inner structure
of ancient bronzes from early Chinese dynasties (1700-221 BCE). One
of their most powerful investigative tools is the Advanced
Photon Source at Argonne,
the most brilliant X-ray source in the Western Hemisphere.
Argonne researchers Dean Haeffner and Jon Almer, along with Professor David
Dunand and post-doctoral researcher Marcus Young from Northwestern University
and Francesca Casadio and Suzanne Schnepp from the Art Institute of Chicago,
work together to understand the creation and corrosion of ancient Chinese bronzes.
“It's an opportunity to understand the story of the craftsmen who created
the vessel,” Young said, “and understand their process of working with bronze
and the creation of such ancient vessels.”
Understanding the process is of particular interest to Young, who became interested
in science after studying fine arts at the University
of North Texas — he holds
two bachelor's degrees in fine arts, one in ceramics and another in sculpture.
Working for some time as an artist and selling his art, currently available
at his website, myinfinitevision.com,
he also became interested in understanding the process of creating vessels
by using a from-scratch approach, such as making his own glazes, clays, and
kilns. This interest in the science of art led him to a third bachelor's degree,
this time in metallurgical and materials engineering from Colorado
School of Mines, and from there to his doctoral thesis entitled, “Strain
measurements and imaging of metal matrix composites using high-energy X-rays,”
which was completed in 2006 from the Materials Science and Engineering department
at Northwestern University.
The high brilliance of X-ray beams available at the Advanced Photon Source
permits the use of small beams for diffraction studies, as well as for phase-enhanced
imaging for higher contrast than traditional X-ray absorption methods. This
means that the researchers can
non-destructively sample a number of small areas of the artifact quickly
and can also penetrate about 100 times
deeper than conventional X-rays.
“One of the things this technique allows us to see is the texture of the grains
in the material,” Haeffner said. “If the bronze was cast in ingots, there should
be very little texture in the grains; metals usually get texture from mechanical
processing, such as rolling. So we get a clue of how the object was made, what
sort of technology was used, what tools they had.
“Being able to sample a number of small sample spots all over the
vessel at one time gives us truly comprehensive results," he said, "which helps
give us a more thorough understanding of how the bronze was worked and shaped.”
The researchers found that the vessel's outer corrosion layer,
which is visible optically, is very thin and consists of cuprite and cassiterite.
The bulk of the vessel remains uncorroded and is composed of a lead phase and
a copper-tin intermetallic phase, which was observed as large, untextured
grains, indicating that the vessel was produced by casting, rather than by
cold- or hot-working. Results from an earlier study on an ancient Chinese bronze
fragment can be found in Applied
Physics A (83) 163-168 (2006).
After the success of this initial study on a bronze fragment in 2006, the
researchers are continuing in their study investigating complete, large-size
Chinese bronze vessels from the Art Institute of Chicago, and Young is working
as a post-doctoral researcher on the project under a Mellon Fellowship, which
will be completed in July 2007. His next stop is the Ruhr
University in Bochum, Germany, where he'll be continuing similar research as a Humboldt fellow. — Catherine Foster
For more information, please
contact Steve McGregor (630/252-5580 or media@anl.gov)
at Argonne.
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