The use of metallic deformatble containers- gaskets between diamond
anvils in an apparatus (DAC) helps to carry out studies under
quasi-static conditions at high pressures. The deformable container-
metal gasket together with the basic functions of pressure generation
and formation of cell for object study provides the anvils peripheral
area thus reducing a probability of failure at high pressures.
Several theoretical models were used to study the metal gasket
behaviour during the generation of pressure and the support of the
anvils peripheral area. The study of the metal gasket behaviour under
loading was based upon the elastic- plastic deformation study of a
gasket made of stainless steels in the pressure range studied.
The operation of the gasket in the DAC is analyzed and some practical
relevant conclusions for users of DACs in the submegabar pressure
range are given. Two distinct regimes are found, one where the gasket
is at the maximum thickness and the DAC is intrinsically unstable, and
the other where the gasket in thin and the cell is stable in
operation, so that there are good reasons to use pre-indented gaskets,
of thickness rather less than usually recommended. Force- pressure
plots are shown to give valuable information in routine use, and their
interpretation is discussed. Our calculations show that in the range
of submegabar pressure in the working cell, i.e. into the pressure
range, which is of interest to studies of biological objects, there is
the maximum in distribution of contact loads q along cell radius. As a
result the decrease of cell diameter with the growth of contact loads
is observed. We suppose that the making allowance for this effect is
necessary condition at the development of specific experimental
methods.
The obtained experimental and theoretical results makes it possible to
choose the optimum of gasket parameters and properties for the
deformable containers, thus providing the submegabar pressure
generation functions and the support of the diamond anvils peripheral
area.
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