Sol-gel assisted synthesis of TiB2-B4C composite powder

Composite powders containing titanium diboride and boron carbide have been prepared by sol-gel method at 1450 degrees 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 B2O3/TiO2, 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 TiB2, B4C, and TiC phases after heat treatment at 1450 degrees C at mole ratio of B2O3/TiO2 = 4.5, C/B2O3 = 2.4. With increasing the content of boron oxide, the unwanted phases such as TiC and C were reduced. TiB(2)and B4C composite powders (similar to 5 mu m diameter) containing residual carbon (<4 wt%) were synthesized using the mole ratio of B2O3/TiO2 = 10 and C/B2O3 = 1.9 at low temperature of 1450 degrees C.