Studying the incorporation of WC to make B4C-TiB2 system more interesting for armour applications

B4C is a lightweight ceramic with a unique combination of physical and mechanical properties but also very difficult to densify, also under pressure, below 2000 °C. The mixture with TiB2 is an advantageous combination because it improves the toughness and the fracture resistance making B4C electrically conductive and suitable for EDM technique. However, this system needs very high temperature and pressure to achieve full densification. Our idea was to used WC as sintering aid to study the influence of the densification and properties for B4C-TiB2 system. We explored the effect of WC addition with several processing methods (soft ball milling, high energy milling, using grinding media WC for both, and addition powder of WC) studying 50v%B4C / 50v%TiB2 compositions. High energy milling seems very attractive due to the combination of contamination and reduction of mean grain size of the powder. Thanks to this process, the sintering temperature decreased to 1860 °C giving high values of hardness and strength, 860±40 MPa and 28.5±1.4 GPa respectively. Different mixtures of B4C-TiB2 spanning from B4C-rich to TiB2-rich compositions were studied using the high energy milling method. The highest value of hardness (32±1.8 GPa) was obtained for 75v%B4C / 25v%TiB2 composition while the highest value of fracture toughness (5.1±0.1 MPa m0.5) was obtained for 25v%B4C / 75v%TiB2 composition.