Titanium-titanium boride matrix composites prepared in-situ under conditions combining combustion processes and high-temperature shear deformation

Abstract

In this work, we have determined regularities for the effects of conditions combining combustion processes and high-temperature shear deformation on the formation of the structure, phase composition, and physical and mechanical properties of compact composite materials based on TiB-(20–40 wt %) Ti. Compact materials with dimensions of 55 × 100 × 8 mm have been obtained, from which samples of two types have been prepared: (type 1) parallel to the applied loading when obtaining composites and (type 2) perpendicular to the applied loading. It has been found that the resulting composites have the texture of TiB whiskers depending on the direction of deformation of the synthesized material. It has been established that the size of TiB whiskers decreases up to 10 times with an increase in the proportion of free titanium in the composite material and a decrease in the delay time before pressure is applied. A mechanism for crack propagation during three-point bending is proposed, on the basis of which we have explained improved mechanical characteristics of the obtained composites depending on the texturization of TiB whiskers. The mechanical characteristics are compared with similar materials obtained by the SHS/PHIP method, as well as with known ceramics based on SiSiC and B4C obtained by the SPS and HIP methods.