Synthesis, structure, and properties of polymer‐derived, metal‐reinforced boron carbide cermet composites

Abstract

We report on a novel polymer‐derived synthesis approach that yields boron carbide monoliths and metal‐reinforced B4C cermets. This single‐step approach relies on a preceramic powder blend of boron and an acetylenic resin with a high char yield. At low temperatures below 1500°C and without applied pressures, preceramic precursor reaction bond together and form nanocrystalline refractory B4C matrices. Resulting near net shape boron, carbide monoliths exhibit small crystal grain sizes, maintain chemical purity, and exhibit morphological homogeneity. We reinforce the refractory carbide with five different metals and demonstrate the influence of each on the density, hardness, oxidation stability, and electronic conductivity of resulting cermet composites. We assess the optimal synthesis and reinforcement strategies that tailor these nanostructured materials for inexpensive and high‐performing engineering applications.

Preparation and characterization of novel boron containing nanocomposites with neutron radiation shielding properties

“…The medium‐intensity boron carbide diffraction peaks were the most intense and clear in the composite derivative with 20% B 4 C. Boron carbide density also suppressed the diffraction intensity at 21° caused by the PVA/PEO/PVP blend. Diffraction angles originating from boron carbide are clearly observed at approximately 23°, 25°, 35°, and 38° 29,30 . Figure 7B shows the XRD patterns of PVA 90 /PEO 5 /PVP 5 ‐BN %5 , PVA 90 /PEO 5 /PVP 5 ‐BN %10 , and PVA 90 /PEO 5 /PVP 5 ‐BN %20 .…”

“…28 According to the XRD pattern shown in Figure 6, it is confirmed that the interaction and miscibility between PVA, PVP, and PEO are due to the existence of the O H and C O groups and the strong interaction between them. 29,30 Figure 7B shows the XRD patterns of PVA 90 /PEO 5 /PVP 5 -BN %5 , PVA 90 /PEO 5 /PVP 5 -BN %10 , and PVA 90 /PEO 5 /PVP 5 -BN %20 . Boron nitrite, unlike boron carbide, shows less diffraction.…”