Sol‐gel assisted synthesis of TiB2‐B4C composite powder

Abstract Composite powders containing titanium diboride and boron carbide have been prepared by sol‐gel method at 1450°C using titanium isopropoxide (titanium precursor), boric acid (Boron precursor), sucrose (carbon source), and acetic acid (AcOH) as a solvent. The effect of boron source (trimethyl borate and boric acid) and B 2 O 3 /TiO 2 , C/B 2 O 3 mole ratios of starting materials on the final phases has been studied. The progress of reactions was determined using thermal analysis (TGA‐DTA). The resultant powders were characterized by X‐ray diffraction (XRD) analysis and field‐emission scanning electron microscope (FESEM). XRD patterns confirmed the formation of TiB 2 , B 4 C, and TiC phases after heat treatment at 1450°C at mole ratio of B 2 O 3 /TiO 2 = 4.5, C/B 2 O 3 = 2.4. With increasing the content of boron oxide, the unwanted phases such as TiC and C were reduced. TiB 2 and B 4 C composite powders (~5 µm diameter) containing residual carbon (<4 wt%) were synthesized using the mole ratio of B 2 O 3 /TiO 2 = 10 and C/B 2 O 3 = 1.9 at low temperature of 1450°C.