CMR Scientific Research and Resulting Technology Transfer Activities
& Accomplishments
This research conducted by the UD-CCM team focuses on the development
of colloidal shear thickening fluids (STF) for use as body armor. Colloidal
STFs are composed of submicron, rigid particles dispersed at high volume
fractions within a carrier fluid. These fluids undergo a novel transition
from a fluid-like state at low flow rates, to a solid response, if forced
to flow at higher shear rates. The fundamental understanding of this flow-induced
solidification was performed at University of Delaware under the PhD research
of Dr. Jonathan Bender (currently on the faculty of the Univ. of South Carolina)
and Dr. Brent Maranzano (currently with Rohm and Haas Corp.) over the past
decade under the auspices of the National Science Foundation. "Working
with scientists at the ARL through the UD-CCM, we have been able to harness
this novel, but natural phenomenon for practical applications, which in
this case is protecting people from ballistic threats. This research has
potential benefits in both civilian and military applications," says
Wagner.
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Dr.
Norman Wagner, professor in the University of Delaware’s Chemical
Engineering department with colleagues Dr. Young Sil Lee, a post doctoral
fellow, Ron Egres, a first year graduate student and Dr. Eric Wetzel of
the Army Research Laboratory (ARL) won the Paul A. Siple Memorial Award
for their research titled,
"Advanced Body Armor Utilizing Shear Thickening Fluids".
The highly coveted Siple Award (also known as the Silver Medallion Award)
was presented to the research group this past December during the 23rd
Army Science Conference on "Transformational Science and Technology
for the Army," in Orlando, Fla. The Siple Award, presented biannually,
is named for Dr. Paul A. Siple, the first U.S. scientific attaché
to Australia and New Zealand and Antarctic explorer. It also includes
a silver medallion for achievement.
RAPID AUTOMATED INDUCTION LAMINATION
The establishment of a science-base for electromagnetic heating of composites led
to a new process for developing novel, high-volume, carbon thermoplastic
(AS4/PEI) laminate models and fabrication. Through a Dual-Use
Applications Program (DUAP) funded by the U.S. Army Armaments
Research Development and Engineering Center (ARDEC) and the Defense
Advanced Research Projects Agency (DARPA), a team comprising UD-CCM,
ARL, and Alliant Techsystems developed Rapid Automated Induction
Lamination (RAIL). RAIL relies on induction rapid volumetric heating
for multi-layer consolidation at very rapid rates; a 5-10 ft/min
was demonstrated on 1-ft-wide panels.
The UD-CCM research team and Accudyne Systems (Newark, DE) fabricated an
experimental laminator based on the RAIL process with hardware
specifications generated using a model-based design approach.
Process optimization and proveout were followed by factory implementation
at the Alliant Techsystems facility (Rocket Center, W.V.) within
six months for production of the M829A3 sabot.
The RAIL process has significant potential as a cost-effective replacement
for conventional processes (autoclave and vacuum debulk) for carbon-fiber-based
thermoplastics, as it is independent of the resin system, and
it has the potential to be integrated with thermoforming for the
high volume production of net-shape carbon/thermoplastic parts.
Although RAIL was developed to fabricate the M829A3 sabot, it
has potential applications in automotive and aerospace products.
CURIE TEMPERATURE CONTROL OF THE INDUCTION
HEATING PROCESS
A method for Curie temperature control of the induction
heating process using magnetic nanoparticles was developed, including
the synthesis of particles with tailorable Curie temperatures.
The method was transitioned to Triton Systems for application
in Triton's SmartBond technology, which uses a family of ferromagnetic
particles known as "susceptors" that absorb magnetic
energy. When exposed to alternating magnetic fields, the susceptors
respond by generating heat until a preset maximum temperature,
known as the Curie temperature, is reached.
By manipulating the chemistry of these susceptors,
a Curie temperature from 56 deg. C to 475 deg. C can be precisely
established. Unlike other heating technologies that externally
transfer heat from an energy source, SmartBond is designed to
selectively deliver heat only where it is necessary, enabling
precision joining and heating of complex structures. Triton was
named Grand Winner of the Small Business Innovative Research (SBIR)
Technology of the Year Award for 2000.
DIFFUSION-ENHANCED ADHESION (DEA) AND
CO-INJECTION RESIN TRANSFER MOLDING (CIRTM)
DEA is a novel bonding method that was selected as one of only
seventeen technologies
nationwide to be highlighted in a 1997 DoD publication. CIRTM
(U.S. Patent No. 6,048,488) is a new manufacturing method that
enables simultaneous injection and cure of multiple resins for
multifunctional hybrid composite structures.
DEA and CIRTM were invented at UD-CCM to address the
cost and performance barriers
that hinder the introduction of composite materials for
ground-vehicle applications. When applied in tandem, these two
composite processing technologies enable the manufacture of lightweight
composite/ceramic integral armor, offering significant cost-reduction
and performance enhancement over existing defense industry practices.
CMR research on DEA and CIRTM technologies established the fundamental
science base to provide affordable, lightweight, multi-functional
armor for the Objective Force. Furthermore, this new capability
has been transitioned to the U.S. Navy for an application demonstration
article for fire-hardened top-side structures.
INTERPHASE SCIENCE
Under the CMR program, the Dynamic Interphase Loading Apparatus
(DILA) was developed at UD-CCM to determine the high-strain-rate
properties of the interphase. A specialized version of a micro-indentation
or fiber-push out test, DILA allows for testing at a wide range
of loading rates and environmental exposures. This apparatus supports
evaluating the potential for absorbing order-of-magnitude higher
amounts of energy by tailoring the nanometer-scale fiber/matrix
interphase within the composite.
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