Synthesis and consolidation of titanium diboride

Titanium diboride (TiB2) is one of the candidate materials for high temperature structural applications and also for control rod elements in high temperature nuclear reactors. This paper presents the experimental data on the synthesis, consolidation to dense pellets and property evaluation of TiB2 carried out in laboratory scale. TiB2 powder was prepared by the reduction of titanium oxide with boron carbide and carbon, purified by high temperature – high vacuum treatment and milled to obtain micron sized particles. The powders were characterized by XRD, chemical analysis and laser particle size analyzer. The reduction process was optimized for the production of titanium boride of ∼1 μm size median dia with oxygen, carbon and nitrogen contents close to 0.5% each. Studies on densification of TiB2 powders by hot pressing were conducted. Pellets with a high density of 97.56% ρth were prepared by hot pressing at 1800 °C. Hardness of this sample was measured as 26 GPa, fracture toughness as 5.3 MPa m1/2 and thermal conductivity as 59.44 W/m/K at 500 °C.