On Modeling of Synthesis Process of Boron Carbide Based Nanocomposites

Abstract

Nanocomposites based on boron carbide B4C are hard materials with wide field of applications in modern technologies. A system of first-order ordinary differential equations that simulates the process of chemical synthesis of nanopowders of B4C–TiB2 compositions containing titanium diboride (TiB2) as an additional phase is suggested and resolved numerically for a typical ratio of reaction constants. Reagents and products concentrations are found as time-functions. In this way, the optimal route of production technology of boron carbide-based nanomaterials can be identified.

Mechanical activation effecton the structure and properties of SHS compounds

“…Then the machining stopped about half the time extracting the product as composite particles with a small (several nanometers) size of crystallites depending on the processing conditions. The propagation speed of combustion of mechanically activated composites was slightly higher than for the original mixtures [1,2,8]. The ignition activation energies were identified, which were close to the ignition activation energies of conventional thermites [4].…”

“…A large number of publications are devoted to the study of the influence of mechanical activation on the structure and properties of boron SHS-composites. The results of the study of the structure of mechanicallyactivated powders with different ratio of components and properties of compact materials on their basis are presented in the papers [1,2,3].…”

“…Consequence of alternation of these processes is the homogenization of the particle composition with the increase of the processing time [4,6,7]. As a result, a composite powder is formed with a developed interfacial surface between the components.Repeated intensive mechanical action on the powder mixture leads to the formation of a highly defective, far from the equilibrium atomic structure of composite particles [1,3,5,[8][9][10]. The processing not only reduces the size of the reagents, but it also increases the area of contact between them, cleanses the contact surface from oxide films and other impurities, accumulates defects of the crystal structure.…”

On Demand Degradable h-BN–Fe3O4 Nanocomposite Powders for BNCT Delivery Agents (Focused Mini-Review)

“…In detail they are described in papers [26][27][28] and proceedings of the Paris, Tbilisi and Kyiv conferences together with obtained materials structure and some physical properties: pentacarbonyl. As iron carbonyl is known as a strong poisonous substance, process is conducted in a fume cupboard.…”

Nanopowder Boron Compounds Doped with Ferromagnetic Clusters for BNCT

“…By applying the liquid charge chemical synthesis method, there are produced some boron carbidebased nanocomposites containing ferromagnetic components such as iron Fe and nickel Ni, namely, metal-ceramic nanocomposites containing boron carbide matrix and ternary metallic alloy binder in form of eutectic binary alloy Co-Ti, where Co partially is substituted by nickel Ni: B 4 C/(Co-Ni-Ti) [39][40][41][42][43]. There are also synthesized nano powders of complex compositions, which in addition to boron carbide and cobalt contain metal diborides MeB 2 (Me = Ti or Zr, rarely Hf) and, maybe, tungsten carbide WC at high temperatures (>1600°C) tending to be converted into tungsten boride W 2…”