Borhaltige keramische neutronenabsorberwerkstoffe

Progress in pressureless sintering of boron carbide ceramics – a review

“…Yuan et al [10] reported that relative density and hardness of B 4 C ceramics with the addition of 4 wt-% organic glucose sintered at 2200°C were higher than those of pure B 4 C ceramics sintered at 2250°C. Though sintering proceeds very satisfactory, there are some disadvantages which organism route suffers from: (1) hard agglomerates produced because of polymerisation reactions in the organism; (2) environmental pollution caused by pyrolysis products; (3) insufficient flow behaviour of particles into pressing dies; (4) the fairly complex handing of the organismdoped powders and (5) small amounts of free carbon contained in the final products, which must be avoided in nuclear applications.…”

“…The absolute value of the standard free energy change, according to the thermodynamic data for elementary reactions, for Reaction [1] is much higher than that for Reaction [2] in the range of 1000-1600°C…”

“…Boron carbide (B 4 C) ceramics has many outstanding performance, such as extremely high hardness (Vickers hardness: 3770 kg mm −2 , the only substances harder than B 4 C are diamond and c-BN), high melting point (2427°C), low density (2.52 g cm −3 ), high elastic modulus (450 GPa), high thermoelectromotive force, high chemical resistance, high neutron absorption cross section, high impact and excellent wear resistance [1][2][3]. Because of the valuable properties, B 4 C ceramics is useful for various industrial applications both at room and high temperatures.…”

“…Because of the valuable properties, B 4 C ceramics is useful for various industrial applications both at room and high temperatures. B 4 C ceramics can be used as lightweight ceramic armour, high temperature thermocouples, neutron absorber [2], reactor control rods in nuclear power engineering, polishing media for hard materials, abrasive media for lapping and grinding, and wear resistant components (blasting nozzles, die tips and grinding wheels).…”

“…Recently, spark plasma sintering (SPS), pulsed electric current sintering (PECS) and plasma pressure compaction (P 2 C) methods are gradually applied to the sintering of B 4 C ceramics. The application of SPS, PECS or P2 C can reduce the sintering temperature, shorten holding time, and improve the efficiency as sintering the B 4 C ceramics. Many researchers proposed that B 4 C ceramics added different additives prepared by SPS can acquire better relative density and mechanical properties than that of B 4 C ceramics prepared by pressureless sintering or by hot pressing.…”