Oxidation behavior of titanium boride at elevated temperatures

The oxidation behavior of dense TiB2 specimens was investigated. Hot-presse d TIB2 with 2.5 wt% Si3N4 as a sintering aid was exposed to air at temperat ures between 800 degrees and 1200 degreesC for up to 10 h, The TIE, exhibit ed two distinct oxidation behaviors depending on the temperature. At temper atures below 1000 degreesC, parabolic weight gains were observed as a resul t of the formation of TiO2(s) and B2O3(l) on the surface. The oxidation lay er comprised two layers: an inner layer of crystalline TiO2 and an outer la yer mainly composed of B2O3 When the oxidation temperatures were higher tha n 1000 degreesC, gaseous B2O3 was formed along with crystalline TiO2 by the oxidation process, In this ease, the surface was covered with large TiO2 g rains imbedded in a highly textured small TiO2 matrix.