The electrical resistivity measurements are important piece at analysing and testing of materials. They are used for monitoring reactions in materials during temperature variations, which are phases transformation in solid and solidification of materials and alloys. Most important influence on electrical conductivity are microstructure and size of phases in materials.
In my diploma work I want to discover what influence have graphite lamellas on gray cast iron. We had made three different alloys of gray cast iron, which we poured in different timings in cells for measuring electrical resistivity. The inoculations in melt of gray cast iron is losing the effect over the time, whilst we detect the changes.
For analysis we use electrical resistivity measurements, thermal analysis, chemical analysis, simultaneous thermal analysis, hardness test and optical metallographic analysis. We found that the smaller the microstructure and lowest is concentration of graphite the lower is electrical conductivity.