Dielectric measurement characteristics such as the dissipation
factor, relative permittivity and conductivity as a function
of temperature and frequency have been achieved on composite
materials based on different epoxy resins filled with alumina
inclusions. The analysis of the results show the presence of
porosity and inhomogeneity in these materials.
The study of the dissipation factor, as a function of temperature
at high frequencies, has shown an unexpected absorption phenomenon
in materials designed to be utilized as electrical insulators.
The identification of the entities responsible for this relaxation
shows that the entities result from one of the components of
the material. These results can also confirm the inhomogeneity
of the materials.