Chemical analysis of the level of silicon in the two alloys
was carried out to examine the possible variation of silicon
concentration, especially at different distances to graphite
particles. It was found, however, that in alloy 1 there is significant
heterogeneity in the distribution of the element, but
not as a function of the local distance to graphite particles
(Fig. 4). In this figure, the numbers give the silicon concentration,
in wt%, at the location indicated by the accompanying
crosses (). The micro-inhomogeneity is present in a
form of fields. The silicon content within one field is about
the same. However, the average silicon amount of different
fields may vary significantly. Such heterogeneous distribution
is expected to be present in alloy 2, although the three
limited areas analysed did not show significant variation.