W artykule przedstawiono wyniki w zakresie badania mikrostruktury spiekanych kompozytów srebro-TiO2. Materiał badawczy stanowiły kształtki ze srebra z dodatkiem 2 i 5 % TiO2. Porowate kształtki prasowano pod ciśnieniem 500 MPa oraz spiekano w atmosferze wodoru w temperaturze 800 i 900 °C przez 60 min. Kompozyty poddano badaniom gęstości względnej, a także określono zmiany objętości, twardości, wytrzymałości na zginanie, własności tribologiczne w odniesieniu do czystego srebra. W pracy przedstawiono także mikrostruktury kompozytów otrzymanych w wyniku prasowania, spiekania, doprasowania i ponownego siekania.
The Ag-TiO2 electrical contact materials are produced exclusively by means of powder metallurgy (PM). The properties of PM electrical contacts depend on both their composition and manufacturing process. This means that the particle size, and distribution of the refractory phase, the homogeneity of the microstructure, and amount of porosity affect the electrical, mechanical, and thermo-physical properties of the composite material. Attempts have been made to describe the influence of production process parameters on the microstructure and properties of Ag-TiO2 composites with the focus on volume change during sintering. The compositions of powder mixtures are Ag, Ag + 2 % TiO2 and Ag + 2 % TiO2 in all cases. They were subsequently cold pressed in a rigid die on a single action press. The pressure was 500 MPa. The compacts were sintered in hydrogen at 800 or 900 °C for one hour. The properties of the investigated composites are a complex function of the manufacturing route and TiO2 content. The Brinell hardness of the Ag-TiO2 composites increases with the increased content of oxide, whereas the bending strength seems to be adversely affected by the addition of the titanium dioxide powder. The microstructures of as-sintered Ag-TiO2 materials in Figs 6÷8 illustrate uniform distribution of silver (gray), titanium dioxide (circular gray) and small residual porosity.