Effect of zirconia addition on pressureless sintering of boron carbide

Microstructure, Thermo-Physical, Mechanical and Wear Properties of in-Situ Formed Boron Carbide - Zirconium Diboride Composite

“…However, difficulties in consolidation, poor fracture toughness and moderate oxidation resistance restrict the widespread use of B 4 C [1,3]. Preparation of in-situ formed B 4 C composites containing ZrB 2 appears as a viable solution to overcome the above limitations [22]. Although in-situ formed B 4 C-ZrB 2 composites were reported in literature, the detailed characterization with respect to microstructure, thermophysical, mechanical and wear properties are rather limited.…”

“…Sairam et al [19] reported fully dense B 4 C-HfB 2 composites obtained by in-situ reaction of B 4 C and 2.5 % HfO 2 during hot pressing at a temperature of 1900°C and a pressure of 40 MPa (under vacuum). Similarly, it is reported that the addition of ZrO 2 is beneficial for densification due to the formation of ZrB 2 as a reaction product [22].…”

“…Oxide additions as sintering aids are particularly interesting due to the chemical instability of B 4 C with respect to many oxides [19,22]. The resulting chemical reactions during sintering not only enhances the densification but also improves the thermo-mechanical and physical properties of dense bodies via the formation Ceramics -Silikáty 62 (1) 15-30 (2018) of reaction products such as carbides or borides [3,19,22,23].…”

“…The resulting chemical reactions during sintering not only enhances the densification but also improves the thermo-mechanical and physical properties of dense bodies via the formation Ceramics -Silikáty 62 (1) 15-30 (2018) of reaction products such as carbides or borides [3,19,22,23]. The in-situ reaction of B 4 C with Me oxides (Me = Ti, Zr, Cr, V, Hf, Eu, La, and Y) yielded high dense B 4 C based composites (B 4 C-MeB 2 composites) at a lower sintering temperatures with improved mechanical properties compared to monolithic boron carbide [3,19,22,23]. It is reported that TiO 2 addition to B 4 C has helped to enhance the densification, due to the formation of sub-stoichiometric B 4 C by reactive sintering [19,24].…”

Effect of the Addition of Carbon on the Sintering Properties of Boron Carbide Ceramics prepared by Pressureless Sintering

“…B 4 C materials have low density very super hardness,high elasticity modulus,good neutron absorption ability and high chemistry stability．However, it is difficult to achieve high sintered density of boron carbide (B 4 C) ceramics because of the very strong B-C covalent bond,low plasticity, high resistance to gain boundary sliding [1,2]. In addition, the presence of B 2 O 3 on B 4 C surface slows down the densification process.…”