Adapting of sol-gel process for preparation of TiB_2 powder from low-cost precursors

摘要

Sol-gel process has been used for preparation of low-cost titanium diboride (TiB_2) and titanium carbide (TiC) gels and powders. In this process citric acid is used to chelate titanium and boron precursors and ethylene glycol for reaction with this chelate to form organic esters. Thermal behavior of homogeneous gel and relationship between processing parameters and microstructure of powders has been determined. XRD and Raman spectroscopy have been used for a detection of changes during the crystallization. Carbothermal reduction of the gel revealed the formation of TiB_2 and TiC at 1200 deg C for 2h. Well shaped ball-like TiC crystals with the particle size about 200 nm and hexagonal plate-like TiB_2 grains with the particle size about 2 mu m and thickness 200 nm were formed at 1300 deg C for 1 h.