Boron carbide is one of the hardest materials. The combustion method was used to synthesize B4C-TiB2 nanocomposite powder in a B2O3-Mg-TiO2-C system. An experimental study of the formation of B4C–TiB2 nanoparticles was conducted in the thermal explosion mode. A mixture of B2O3:TiO2:Mg:C at a molecular ratio of 3:1:12:1 was chosen to obtain the B4C–TiB2. This powder mixture was milled for differ...

The quest to create superhard materials rarely strays from the use of high-pressure synthetic methods, which typically require gigapascals of applied pressure. We report that rhenium diboride (ReB2), synthesized in bulk quantities via arc-melting under ambient pressure, rivals materials produced with high-pressure methods. Microindentation measurements on ReB2 indicated an average hardness of 4...

We review the thin film growth, chemistry, and physical properties of Group 4-6 transition-metal diboride (TMB2) films with AlB2-type crystal structure (Strukturbericht designation C32). Industrial applications are growing rapidly as TMB2 begin competing conventional refractory ceramics like carbides nitrides, including pseudo-binaries such Ti1-xAlxN. The comprises graphite-like honeycombed ato...

Hardness was measured for six different nominally pure and single-phase high-entropy diboride ceramics with the AlB2 structure that were produced by a two-step process. Most of had relative densities greater than 99.5%. Vickers hardness average values ranged from 21.0 GPa to 25.4 at load 9.81 N, while increased range 33.1 48.3 0.49 N. Among compositions, highest N 48.3±2.3 (Cr0.2Hf0.2Ta0.2Ti0.2...

We investigate the potential for hydrogen storage of a new class of nanomaterials, metal-diboride nanotubes. These materials have the merits of a high density of binding sites on the tubular surfaces without the adverse effects of metal clustering. Using the TiB2 (8,0) and (5,5) nanotubes as prototype examples, we show through first-principles calculations that each Ti atom can host two intact ...