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Nonequilibrium Interface and Surface Dynamics 2007
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Ductility of thin metal films on polymer
substrates modulated by interfacial adhesion
CSIC Building (#406),
Seminar Room 4122.
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Ductility of thin metal films on polymer substrates
modulated by interfacial adhesion
Teng Li
University of
Maryland
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Abstract:
Thin metal films, deposited on polymer substrates,
are used in flexible macroelectronic devices as
electrodes and interconnects. When a laminate of a
thin metal film on a tough polymer substrate is
stretched, the metal film may rupture at strains
ranging from a few percent to a few tens of percent.
This variation in the ductility of the metal film is
modulated by the adhesion of the metal/polymer
interface. To study this modulation, here we use the
finite element method to simulate the co-evolution
of two processes: debonding along the interface and
necking in the metal film. We model the interface as
an array of nonlinear springs, and the metal and the
polymer as elastic-plastic solids. The simulation
shows that necking of the film is accommodated
mainly by interfacial sliding, rather than
interfacial opening. Depending on the resistance of
the interface to sliding, the metal film can exhibit
three types of tensile behavior: the film slides and
ruptures at a small strain by forming a single neck,
the film slides and deforms to a large strain by
forming multiple necks, and the film deforms
uniformly to a very large strain without sliding and
necking. Our results shed light on improving the
ductility of thin metal films on polymer substrates. |
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