Boron carbide is a strategic material, finding applications in nuclear industry, armour for personnel and vehicle safety, rocket propellant, etc. Its high hardness makes it suitable for grinding and cutting tools, ceramic bearing, wire drawing dies, etc. Boron carbide is commercially produced either by carbothermic reduction of boric acid in electric furnaces or by magnesiothermy in presence of carbon. Since many specialty applications of boron carbide require dense bodies, its densification is of great importance. Hot pressing and hot isostatic pressing are the main processes employed for densification. In the recent past, various researchers have made attempts to improve the existing methods and also invent new processes for synthesis and consolidation of boron carbide. All the techniques on synthesis and consolidation of boron carbide are discussed in detail and critically reviewed.

Synthesis and consolidation of boron carbide: a review

Ceramic materials for fusion

The thermal and electrical conductivities, fracture strength, swelling, and microstructure of sintered alpha-phase SiC and siliconized reaction-bonded SiC materials were studied before and after irradiation with reactor neutrons. The effects of helium gas on the properties were studied using boron enriched in /sup 10/B to produce helium from /sup 10/B(n,..cap alpha..)/sup 7/Li. The decrease in thermal conductivity after irradiation is due to enhanced phonon scattering by radiation-induced defects. Electrical, mechanical, and thermal properties exhibit partial recovery after heat treatment to 1000 to 1500 K. An overall consistency is observed in radiation-produced property changes and annealing and a model is presented to explain the changes.

C.K.H. DuBose

Papers

Transmission electron microscopy of irradiated boron carbide.