B4C-TiB2 composites were contaminated with WC to study the effect on densification, microstructure and properties. WC was introduced through a mild or a high energy milling with WC-6 wt%Co spheres or directly as sintering aid to 50 vol% B4C / 50 vol%TiB2 mixtures. High energy milling was very effective in improving the densification thanks to the synergistic action of WC impurities, acting as sintering aid, and size reduction of the starting TiB2-B4C powders. As a result, the sintering temperature necessary for full densification decreased to 1860 degrees C and both strength and hardness benefited from the microstructure refinement, 860 +/- 40 MPa and 28.5 +/- 1.4 GPa respectively. High energy milling was then adopted for producing 75 vol% B4C/25 vol% TiB2 and 25 vol% B4C/ 75vol%TiB2 mixtures. The B4C-rich composition showed the highest hardness, 32.2 +/- 1.8 GPa, whilst the TiB2-rich composition showed the highest value of toughness, 5.1 +/- 0.1 MPa ma(0.5).
Hard and easy sinterable B4C-TiB2-based composites doped with WC
Failla S;Melandri C;Zoli L;Sciti D
2018
Abstract
B4C-TiB2 composites were contaminated with WC to study the effect on densification, microstructure and properties. WC was introduced through a mild or a high energy milling with WC-6 wt%Co spheres or directly as sintering aid to 50 vol% B4C / 50 vol%TiB2 mixtures. High energy milling was very effective in improving the densification thanks to the synergistic action of WC impurities, acting as sintering aid, and size reduction of the starting TiB2-B4C powders. As a result, the sintering temperature necessary for full densification decreased to 1860 degrees C and both strength and hardness benefited from the microstructure refinement, 860 +/- 40 MPa and 28.5 +/- 1.4 GPa respectively. High energy milling was then adopted for producing 75 vol% B4C/25 vol% TiB2 and 25 vol% B4C/ 75vol%TiB2 mixtures. The B4C-rich composition showed the highest hardness, 32.2 +/- 1.8 GPa, whilst the TiB2-rich composition showed the highest value of toughness, 5.1 +/- 0.1 MPa ma(0.5).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.