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Modelling of nanoindentation to simulate thin layer behaviour |
R.
MAJOR, P. LACKI, J.M. LACKNER, and B. MAJOR |
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The work presents a computer simulation realized with the ADINA program concerning nanoindendation test. A shape of nanoindenter
was proposed to be similar to the real surgical tools. The theoretical model was used to predict phenomena which would appear in
practice. The contribution of the TiN coating thickness to the implant rigid properties was simulated. Three types of extortion conditions could
be considered, i.e., short contact with surgery tool (i); long continuous contact with natural tissue (ii); long cyclic contact with natural tissue
(iii). In the first part of the work, the authors focused on the first type of extortion (i). The second part of the work is dedicated to the calculations
of temperature impact to layer behaviour. Two layer thicknesses are considered i.e., 250 nm and 50 nm. The examined coatings find serious
practical applications as a blood-contacting material in medicine. The coatings were subjected to transmission electron microscopy investigations.
Columnar mechanism of film growth controlled by kinetic process is stated to operate for the considered range of layer thickness.
Plasma temperature is observed to influence the substrate behaviour. Examinations of thinner layers, i.e. under 100nm, revealed higher degree
of smoothness and uniformity, which could be related to the operation of the surface diffusion mechanism at the early stage of deposition. The
physical explanation of TEM images was based on the finite element calculations of the temperature distribution using the ADINA program . |
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Keywords: |
nanoindentation, finite element modelling, temperature, stress, strain, thin
layers |