• Borodianska, H.
• Badica, P.
• Demirskyi, D.
• Kuncser, A.

Abstract

<jats:title>Abstract</jats:title><jats:p>High density (99.5%) ceramic composite composed of titanium boride and boron carbide (70/30 vol%) was obtained by spark plasma sintering and was tested by 3-point bending test in Ar atmosphere at 1800 °C. Bending strength was high, around 1.1 GPa. The strength–strain curve presents a peculiar shape composed of three regions where elastic and plastic deformations are active with a different weight. Based on transmission electron microscopy observations we propose a process of mechanical energy absorption driven by shear stress in the boron carbide crystals: stacking faults with (1-11) and (011) stacking planes and twins with (1-11) twinning plane rearrange into nano-twins with (10-1) twinning planes, orthogonal but equivalent to the initial ones. This rearrangement mechanism provides in the first instance a plastic signature, but further contributes strengthening.</jats:p>

Topics

• density
• polymer
• strength
• carbide
• composite
• transmission electron microscopy
• bending flexural test
• Boron
• titanium
• boride
• sintering
• stacking fault