Abstract:
Gray Iron samples alloyed with tin in small proportions
have been studied for their electrical resistivity properties.
The Tin content were varied in steps of 0.05% within a total
range of 0.00-0.35% Tin. Three independent sets of samples were
prepared. Measurements were made on each set of samples in the
temperature range from 85-1173K. In general each sample shows
positive value of dP /dT over a very wide temperature range,
from 85 to 773K(measurements below 85K have not yet been done).
The numerical values of dP /dT for the different samples of the
same series of alloy, however, differ substantially. A
graphical plot of dP /dT against % of Tin shows a significant
inflexion at about 0.1% Tin for each of the three sets of
samples. This is suggestive of some ordering effect in the
composition range of 0.1-0.15% Tin. Interestingly The British
cast and Iron Research Association has also reported a definite
magnetic transition in similar alloys at a composition of about
0.1% Tin.For an understanding of the Physics of this transition,
a good deal of further investigations would be required.
Magnetoresistance measurements of these materials were also
undertaken at room temperature. These are very preliminary
measurements, and are only significant in so far as that they do
indicate significant magnetoresistance effects. These measurements
need to he followed up further, and one may expect to observe
some significant effect in the composition range of 0.1-0.15%
Tin.There is very little information available in literature
on this material, and so the present study is useful in its own
right.
