238 Prakt. Met. Sonderband 38 (2006) 
4. CONCLUSIONS > 
The experiments and the investigations show that the microstructural changes during " 
internal oxidation of Ag-Sn alloy are strongly dependent on the internal oxidation 
temperature. At the highest temperature the perfectly disperse and homogeneous 
distribution of the oxide particles SnO-, in the silver matrix was found, while at the lower 
oxidation temperature formation of inner oxide bands and distribution of oxide particles 
along the grain boundaries is predominated. Moreover, the in-situ electrical resistance 
measurements enable monitoring of the internal oxidation process continuously and 
nondestructive. From the measured electrical resistance curves it is possible to identify: (i) 
the parabolic kinetics of the process, (ii) starting and end point of the internal oxidation and 
consequently (iii) the time needed for the total internal oxidation of the alloy. 
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