On the Optimization of the Microstructure in Powder Metallurgical Ag–SnO 2 –In 2 O 3 Contact Materials

Since their introduction, contact materials based on Ag– SnO 2 have been significantly improved with respect to their applicability and their performance. Only recently, however, have the manufacturers embarked upon optimizing the microstructure of these materials, e. g., determining the optimal particle size, improving homogeneity, or tailoring of the phase arrangement, rather than solely modifying the material’s composition. The intent of this paper is to describe a process for the production of composite powders for electric contacts, the versatility of which allows the modification of all three parameters: particle size, homogeneity, and phase arrangement. Results are presented on a new generation of Ag–SnO 2 –In 2 O 3 contact materials that were manufactured with this process.