The processing and properties of Ag-W-TiO2 composites
Marcin Madej
Quarterly No. 3, 2014 pages 163-168
DOI:
keywords: tungsten, titanium dioxides, silver, sintering, electrical contacts
abstract Silver-based composites can be divided into two types: type 1 uses a pure element or carbide as the dispersed phase; type 2 uses oxides as the dispersed phase. In this work was shown the combined effect of small additions of oxides with tungsten. Attempts have been made to describe the influence of production process parameters on the microstructure and properties of Ag-W-TiO2 composites. The compositions of the powder mixtures are Ag + 10% W + 1% TiO2, Ag + 20% W + 1% TiO2, Ag + 30% W + 1% TiO2. The powder mixtures were prepared by tumbling in a Turbula type mixer. The mixtures were then subjected to a double-press/double-sinter process. The studies show that a nearly fully-dense material made of silver, tungsten and TiO2 powders cannot be achieved by double pressing and double sintering. The relative density near 90% of the composites was achieved. The electrical conductivity and bending strength of Ag-W-TiO2 materials decrease with tungsten content, but the hardness of Ag-W-TiO2 materials increase with the amount of tungsten. The Ag + 10% W + 1% TiO2 and Ag + 20% W + 1% TiO2 materials studied in this work also show relatively homogenous distribu-tion of the tungsten and TiO2 additions.