• Borodianska, H.
• Badica, P.
• Pasuk, I.
• Demirskyi, D.
• Suzuki, T. S.
• Kuncser, A.
• Li, P.
• Grigoroscuta, M. A.
• Vasylkiv, O.

Abstract

<jats:title>Abstract</jats:title><jats:p>Mixtures of B<jats:sub>4</jats:sub>C, α-AlB<jats:sub>12</jats:sub> and B powders were reactively spark plasma sintered at 1800 °C. Crystalline and amorphous boron powders were used. Samples were tested for their impact behavior by the Split Hopkinson Pressure Bar method. When the ratio <jats:italic>R</jats:italic> = B<jats:sub>4</jats:sub>C/α-AlB<jats:sub>12</jats:sub> ≥ 1.3 for a constant B-amount, the major phase in the samples was the orthorhombic AlB<jats:sub>24</jats:sub>C<jats:sub>4</jats:sub>, and when <jats:italic>R</jats:italic> &lt; 1 the amount of AlB<jats:sub>24</jats:sub>C<jats:sub>4</jats:sub> significantly decreased. Predictions that AlB<jats:sub>24</jats:sub>C<jats:sub>4</jats:sub> has the best mechanical impact properties since it is the most compact and close to the ideal cubic packing among the Al-B-C phases containing B<jats:sub>12</jats:sub>-type icosahedra were partially confirmed. Namely, the highest values of the Vickers hardness (32.4 GPa), dynamic strength (1323 MPa), strain and toughness were determined for the samples with <jats:italic>R</jats:italic> = 1.3, i.e., for the samples with a high amount of AlB<jats:sub>24</jats:sub>C<jats:sub>4</jats:sub>. However, the existence of a maximum, detectable especially in the dynamic strength vs. <jats:italic>R</jats:italic>, indicated the additional influence of the phases and the composite’s microstructure in the samples. The type of boron does not influence the dependencies of the indicated mechanical parameters with <jats:italic>R</jats:italic>, but the curves are shifted to slightly higher values for the samples in which amorphous boron was used.</jats:p>

Topics

• impedance spectroscopy
• microstructure
• amorphous
• phase
• strength
• composite
• hardness
• Boron
• sintering