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Abstract: Nanoindentation
tests performed in an atomic force microscope have been utilized to
directly measure the mechanical properties of single crystal copper thin
films fabricated by the vacuum vapor deposition technique.
Nanoindentation tests are conducted at various indentation depths to
study the effect of indentation depths on the mechanical properties of
thin films. The elastic modulus of the single crystal copper film at
various indentation depths is determined as 67.0 GPa±6.9 GPa on average
which is in reasonable agreement with the results reported in
literature. The indentation hardness constantly increases with
decreasing indentation depth, indicating a strong size effects. In
addition to the experimental work, molecular dynamics simulations of
nanoindentation process have been conducted to elucidate the mechanics
and mechanisms of nanoindentation of thin films. MD simulations results
show that due to size effect the plastic deformation via amorphous
transformation is more favorable than via the generation and propagation
of dislocations in nanoindentation of single crystal copper thin films.
Simulations results also elucidate the reason of size effects from the
atomistic point of view.
Key words:Nanoindentation
Thin film Atomic force microscope Molecular dynamics Mechanical
properties
CLC No: TH11
O484
国家自然科学基金(50175017)和哈尔滨工业大学跨学科交叉性研究基金(HIT.MD.2000.9)资助项目.
Received 20039127, received in revised form 20031015
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