Special Features of the Formation of the Structure and Properties of Materials from the B_4C-TiH_2 Powder System in Reaction Sintering under Pressure

摘要

The results of studying reaction sintering under pressure in the B_4C-TiH_2 system have been discussed. It has been shown that the material structure consists of the B_4C matrix phase and intergranular phase of titanium diboride (borocarbide) having a small mutual solubility of components. Physico-mechanical properties of the materials have been studied depending on the composition. A increase of titanium hydride by 9 wt% has been shown to decrease hardness by 16%, to affect the bending strength (～500 MPa) only slightly, and to increase the fracture toughness by 60% - up to 6.0 MPa·m~(1/2) and the thermal expansion coefficient - by 90% - up to 5.2 × 10~6/K.