The
MRSEC
participates
in
a
number
of
fruitful
outreach
activities
with
other
institutions.
This
outreach
takes
of
the
form
of
collaborations
based
on
shared
interests
and/or
resources,
personnel
exchanges
with
other
laboratories,
and
the
organization
of
meetings
and
work
shops.
Several
collaborations
are
listed
below.
Those
interested
in
forming
a
collaboration
with
the
MRSEC
should
contact
Prof.
A.
Rollett.
Some
questions
frequently
asked
by
industrial
collaborators
are
addressed
here.
- M.
Upmanyu,
Colorado
School
of
Mines,
and
A.D.
Rollett,
CMU
MRSEC
Non-linear
boundary migration
kinetics. When
boundary curvatures
are based
on nanoscale
microstructures, the
driving forces
are high
compared to
the thermal
energy. The
non-linear migration
rate-driving force
response observed
in molecular
dynamics may
be a reflection
of the
loss of
linearity that
has been
assumed since
the classical
analysis of
Turnbull in
the 1950s.
- V.
Randle,
University
of
Wales
Swansea,
and
G.S.
Rohrer,
CMU
MRSEC
We
are studying
changes in
the grain
boundary plane
distribution during
the sequential
thermomechanical processing
used for
grain boundary
engineering of
materials with
a high density
of annealing
twins. We
are applying
our new
stereological analysis
technique to
determine grian
boundary character
distributions and
obtain a better
understanding the
influence of
the grain
boundary plane
on the
macroscopic properties.
- C.
Cornwell
(US
Army/
High
Performance
Technologies
Inc.),
S.
Schoenfeld
and
J.
Clayton
(Weapons
Materials
R&D,
Aberdeen,
MD),
and
A.D
Rollett,
CMU
MRSEC
Developing
numerical 3D
descriptions of
anti-armor materials.
- C.
Liu,
Pennsylvania
State
University,
I.
Livshits,
Central
Arkansas
University,
and
D.
Kinderlehrer
and
S.
Ta'asan,
CMU
MRSEC
Our
collaboration with
Penn State
and Central
Arkansas is
focused both
on developing
analytical principles
that are
necessary to
implement algorithms
for computation
of 3D
grain boundary
networks and
the implementation
of 2D
and 3D
simulations. The
theoretical analysis
in 2D
was instrumental
in development
of a successful
2D model
and has
also yielded
significant mathematical
results. A significant
feature of
the simulations
is the
derivation of
robust statistics
from which
to calibrate
future simulations.
- H.
Weiland,
Alcoa,
A.
D.
Rollett,
CMU
MRSEC,
and
R.
Suter,
CMU
MRSEC
Orientation
Imaging of
Aluminum Alloys.
Our collaboration
with Alcoa
is focused
on collecting
three-dimensional microstructure
data from
Al alloys
used in
aerospace and
automotive structures.
The goals
of the
collaboration are
to provide
fundamental information
on the
motion energy
and mobility
of grain
boundaries in
aluminum using
both the
current characterization
methods of
the MIMP
and the
3D microscopy
methods under
development. The
two areas
of areas
of interest
are (a)
an improved
understanding of
deformation and
annealing in
aluminum alloys
and (b)
an improved
understanding of
the fatigue
fracture process
in partially
recrystallized aerospace
alloys. Information
on grain
boundary properties
measured by
the MRSEC
will be
used by
Alcoa for
modeling of
grain growth
and recrystallization.
- G.
Gottstein,
RWTH
Aachen,
and
A.D.
Rollett,
CMU
MRSEC
Grain
Boundary Mobility
Studies in
Aluminum. Under
the supervision
of advisors
Günter
Gottstein
and
Dimitri
Molodov,
Mitra
Taheri
spent
a summer
at
The
Institut
für
Metallkunde und
Metallphysik, which
was dedicated
to an
apprenticeship or
sorts within
the Interface
Dynamics group.
The group1s
experimental focus
lies in
the areas
of grain
boundaries, notably
structure, mobility,
and the
resulting effects
of microstructure
and chemical
composition on
the motion
of these
boundaries. A large
portion of
her visit
entailed measurement
of boundary
motion via
X-Ray tracking
using bicrystals
(developed onsite).
The later
portion of
her stay
involved further
in-situ studies
of boundary
motion; these
experiments were
performed using
a hot-stage within
a Scanning Electron
Microscope. Mitra
is herself
implementing a hot
stage for
in situ
observations of
boundary motion
in the
OIM system
at CMU.
- T.
Massa,
Kennametal
Incorporated,
and
G.S.
Rohrer,
CMU
MRSEC
We
are working
to identify
which microstructural
parameters of
WC/Co composites
influence toughness
and hardness.
To do
this, we
developing tools
for the
collection
of reliable
microstructural information
and models
for the
behavior of
the composites
under load.
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