High Temperature, High Stakes
The High Temperature Materials Laboratory has expanded into a leading center for transportation innovation.
Conceived in 1973 in the wake
of the first Arab oil embargo,
Oak Ridge National Laboratory's
High Temperature Materials Laboratory
(HTML) was originally envisioned as
a place where the capabilities of high temperature
materials research programs
from industry, academia and government
laboratories would be brought together
to develop structural ceramic materials
for use in highly efficient automotive gas
turbines and heavy-duty diesel engines.
The facility's initial research efforts
resulted in several successful collaborations
with engine manufacturers, including the
development of ceramic turbine components
that could withstand the rigors
of operating for hundreds of thousands
of miles under extreme conditions.
HTML provides the user community with analytical capabilities critical to developing safe and efficient vehicles.
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As the price of oil moderated in the
early 1980s and the urgency of the energy
crisis diminished, HTML director Edgar
Lara-Curzio recalls that the general level
of interest in high-temperature ceramics
also began to wane. "Gradually, HTML's
mission evolved from simply studying
high-temperature materials to analyzing a
greater variety of materials for transportation
technologies," he says. This broadened
focus has enabled HTML scientists, as well
as the users that take advantage of the
facilities' unique equipment, to investigate
materials-related issues across an array
of transportation technologies, including
advanced batteries for plug-in electric and
hybrid electric vehicles; lighter, stronger
vehicle components; and the recovery of
waste heat using thermoelectric materials.
The expansion of HTML's research
mission proved a boon to users. A large
fraction of the facility's users are from
industry, while the rest come from universities
and other national laboratories.
Lara-Curzio is quick to note that HTML
continues its close relationships with engine
manufacturers who have been interested
in structural ceramics for gas turbines and
diesel engines since the user facility was
first established. "We are working with
Cummins on diesel particulate filters and
with Caterpillar, General Motors, Ford and
others on a range of materials for transportation-
related projects."
HTML's user program accommodates
both nonproprietary and proprietary
research—the main difference being that
the former is provided free of charge if
users submit the results of their research
for publication within six months. Proprietary
users pay for the cost of conducting
their research but are not required to share
their results.
Lara-Curzio maintains that user
programs at the national laboratories play
an important role in enabling the development
and implementation of new technologies
by providing users with access to capabilities
that are unavailable to universities
or commercial research facilities. HTML
staff members possess specialized skills in
the area of materials characterization. In
addition to their involvement in the HTML
user program, most conduct research on a
variety of materials used for power generation
and the distribution, storage and use
of energy. The ability of industrial and
academic users to share these capabilities
benefits both parties. "This is our goal and
the role we have played from the beginning,"
Lara-Curzio says.
A better battery
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One of the laboratory's goals is to develop inexpensive electric vehicle batteries that last for at least 10 years.
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One of HTML's top priorities in the past
year was the development of tools that
can be used with microscopes and X-ray
and neutron diffractometers to examine
the internal structure of batteries at the
atomic level as they charge and discharge.
Understanding these processes will enable
HTML researchers to work with manufacturers
to produce batteries that are longer
lasting, safer and more efficient. "In one of
our projects, we are working with Motorola
to study the causes of ‘thermal runaway'
in lithium-ion batteries, a condition that
causes batteries to overheat and catch
fire," Lara-Curzio explains. "We are also
seeking ways to enable batteries to store
more energy so, for example, an electric
vehicle could have a range of hundreds
rather than dozens of miles between
charges. The challenge is to store as much
energy in as little volume with as little
weight as possible."
HTML researchers currently are
working on increasing the power density of
batteries, a process that requires developing
batteries that can provide a lot of
"juice" quickly and recharge in a relatively
short time. Batteries with high power
density would enable an electric vehicle
to accelerate and merge smoothly into
highway traffic or to pass a slower vehicle
comfortably. When the vehicle is parked
at a charging station, the battery could be
charged in a time roughly comparable to
the time it takes to fill a car with gasoline.
Lara-Curzio notes that, even with all
of the other technical challenges, one
of the biggest hurdles on the path to a
better battery is keeping the final product
affordable. "A large fraction of the cost of
electric cars that are available today—or
that will be available in the near future—
is batteries," he says. "We want inexpensive
batteries to last for at least 10 years.
Nobody wants to go to the car dealer
every three years to replace $10,000 worth
of batteries."
Lightweight materials
The greater use of lightweight materials
in vehicles is one of the most straightforward
ways of increasing fuel efficiency.
HTML researchers are working with several
industrial partners to reduce the weight
of vehicles without sacrificing safety. One
of the biggest success stories to come out
of HTML in recent years is Metalsa, a
Virginia-based truck component manufacturer
that sought to reduce the weight of
the truck siderails the company provides
to more than 50 percent of the U.S. truck
market.
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HTML's mission has evolved from simply studying high-temperature materials to analyzing a greater variety of materials for transportation technologies.
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Using instruments at HTML and
ORNL's High Flux Isotope Reactor, Metalsa
engineers and HTML scientists analyzed
how weight and stress were distributed
throughout the siderails. They determined
the optimal locations for cutting holes in the rails, the best methods for cutting the
holes, and the types of steel that would be
best suited for this new, lightweight design.
As a result, Metalsa modified its manufacturing
processes and was able to reduce
the weight of several current production
models by 10 to 20 percent. In the course
of a year, the new designs could save
as much as 30 million pounds of steel,
resulting in an estimated fuel savings of
3.8 million gallons.
Another approach to designing lightweight
vehicle components starts from the
ground up, using aluminum, magnesium
or fiber-reinforced composites instead of
steel. Concerns about these lightweight
"replacement" materials often center on
their crash worthiness. HTML's specialized
equipment not only can assess the amount
of energy that a component will absorb
in a crash but also can provide information
on related issues, such as ways to
strengthen welds, better choices for metal
alloys and performance of lightweight
components under extremes of temperature
and stress.
Reflecting on HTML's 25 years as a
user facility, Lara-Curzio observes that the
facility's wide-ranging materials characterization
capabilities have outgrown its
name. "HTML continues to play a very
important role in addressing one of the
Department of Energy's key priorities: to
reduce the nation's use of petroleum. We
do that by supporting industry, universities
and other national laboratories in the
development of energy-saving technologies.
As we pursued this goal, we expanded
our capabilities in materials characterization
and were aggressive in developing
the infrastructure needed to support the
mission of DOE's Office of Transportation
Technologies." As a result, HTML today is
able to provide the user community with
unique analytical capabilities critical to
developing safe and efficient vehicles.
Lara-Curzio is optimistic about HTML's
future. "Rather than requiring a long
proposal process and a long lead time,
HTML responds on a timescale that meets
users' needs. Our impact is both technologically
and application oriented, in keeping
with our mission to serve the vehicle
technologies community and help solve
their materials problems. We are truly a
national resource for our industrial and
academic users."
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