Effect of iron on the wetting, sintering ability, and the physical and mechanical properties of boron carbide composites: A review

Due to its favorable physical, mechanical and chemical properties, boron carbide (B 4 C) is one of the most important ceramics used in various industries. After diamond and boron nitride with a cubical structure, this material is the third hardest substance known; and due to its low density, large cross-sectional surface area for neutron absorption, excellent chemical stability, and other desired properties, it is considered as a strategic material. The sintering of boron carbide ceramics is very difficult due to the existence of strong covalent bonds in pure boron carbide and its low self-diffusion, high resistance against grain boundary slipping, and low surface energy. For these reasons, many additives have been added to boron carbide, as sintering aids. These additives, in addition to facilitating the sintering of boron carbide, do not have an adverse effect on its properties, and they improve the characteristics of the resulting product. Iron is one of the additives that reduces the sintering temperature and improves the mechanical properties of boron carbide by producing a liquid phase and thus preventing the growth of B 4 C particles. In this paper, the role of iron additive in the wetting, sintering ability, and the physical and mechanical properties of boron carbide composites has been investigated.