The oxidation of titanium diboride and zirconium diboride at high temperatures

Improved Schottky Contacts on n-Type 4H-SiC Using ZrB2 Deposited at High Temperatures

“…40,41 Similar removal of O 2 was also reported during the intentional oxidation of TiB 2 , where B 2 O 3 was observed to form and evaporate rapidly at high temperatures. 42 We believe that the removal of O 2 from the ZrB 2 /SiC interface similarly occurs in the form of oxides such as B 2 O 3 or H 3 BO 3 known to be volatile at 300°C. 43 As the presence of impurities such as O 2 at the interface is known to contribute to undesirable electrical characteristics, this removal of O 2 is possibly the main reason for the improvement of the Schottky characteristics we have observed.…”

Thermochemical and Mechanical Stabilities of the Oxide Scale of ZrB2+SiC and Oxygen Transport Mechanisms

“…Introduction R EFRACTORY diborides (HfB 2 , ZrB 2 ) with 20-30 vol% SiC additive are prominent ultrahigh-temperature ceramics withstanding temperatures 2000 K and above. 1,2 During operation in air its surface is oxidized, giving rise to a crystalline oxide skeleton (HfO 2 , ZrO 2 ) and a silica-rich borosilicate liquid that wets it, [3][4][5][6][7][8][9][10] produced by the reactions:…”

Corrosion of Ceramic Materials

“…At these temperatures, Irving and Worsley (1968) observe that boria is volatilized as soon at is formed and the titania layer controls the oxidation kinetics. Tripp and Graham (1971) developed an experimental TGA technique for oxidation of ZrB2 which measures each component of the paralinear kinetics: consumption of oxygen, weight change due to boria volatility, as well as total sample weight change.…”

“…At temperatures where the volatility of boria is readily observed, oxidation kinetics will therefore follow a paralinear rate law in which oxidation weight gains occur simultaneously with boria volatilization. At temperatures below 1000°C, both Irving and Worsley (1968) and Courtois et al (1993) find protective oxidation behavior of TiB2 attributed to a liquid boria film. A layered oxide is observed at these temperatures and is shown schematically in Figure 47.…”