Electrochemical Behavior of AlB12–AlN Composites in Natural Environments

Phase Composition, Structure and Properties of the Spark Plasma Sintered Ceramics Obtained from the Al12Mg17-B-Si Powder Mixtures

“…It was found that with an increase in the Al 12 Mg 17 -B powder content in the initial powder mixture, the hardness of sintered materials increases. This is due to the formation of compounds based on B 12 icosahedrons (AlB 12 , B 4 Si, B 6 Si) with high hardness [ 3 , 4 , 5 ]. At a content of 70 wt% of Al 12 Mg 17 -B powder in the initial mixture, the hardness of the composite reaches 21.24 ± 1.22 GPa.…”

“…The most common material in this class is titanium diboride TiB 2 , which is reported to have a hardness of up to 35 GPa and an extremely high melting point (3225 °C) that classifies titanium diboride as ultra-high temperature ceramics (UHTCs) [ 1 , 2 ]. Despite their combination of physical and mechanical properties, transition metal diborides have a significantly higher density than higher borides (although their properties are slightly higher): for example, 4.5 g/cm 3 for TiB 2 vs 2.58 g/cm 3 for AlB 12 [ 1 , 3 ]. Higher borides belong to the group of compounds based on B 12 icosahedrons.…”

“…Higher borides belong to the group of compounds based on B 12 icosahedrons. The main compounds based on B 12 icosahedrons are AlB 12 , B 12 C 3 (B 4 C), B 12 Si 3 , B 12 Si 2 (B 4 Si and B 6 Si), and B 12 O 2 (B 6 O) [ 3 , 4 , 5 , 6 , 7 , 8 ]. These compounds exhibit excellent properties at relatively low densities, have extremely high melting points due to the strong bonds of intra- and interclusters B 12 [ 4 ].…”