Enhanced oxidation resistance of ZrB2/SiC composite through in situ reaction of gadolinium oxide in patterned surface cavities

The morphological evolution of the oxide products of Si₃N₄/Al₂O₃ composite refractory under different oxidizing conditions

“…It is deduced that the glassy SiO 2 layer reduces oxygen diffusion and prevents the oxidation to proceed inwards further. 29) This explains the phenomenon that the sample oxidized at 1400°C in dry O 2 obtains the lowest mass gain, especially at long time. The large amount of mullite at 1500°C demonstrates continuous depletion of SiO 2 , which enables O 2 to react with inner exposed Si 3 N 4 layers, resulting in considerable mass gain.…”

Ablation behavior and mechanism of boron nitride - magnesium aluminum silicate ceramic composites in an oxyacetylene combustion flame

“…However, above this temperature, B 2 O 3 evaporates rapidly due to its high vapor pressure [22,23]. The addition of metal oxides or silicides is an effective approach to enhance oxidation resistance in bulk ceramics borides [24,25]. At high temperatures, metal cations incorporate into the borosilicate glass, inducing liquid immiscibility and forming phase separated glasses of high viscosity [26,27].…”

Effect of Internal Current Flow During the Sintering of Zirconium Diboride by Field Assisted Sintering Technology

“…ZrB 2 presents low electrical resistivity (~10 μΩ·cm) and is one of the most promising structural material for high temperature applications due to its unique combination of properties, such as high melting point (3246°C), hardness (23 GPa) and thermal conductivity [from ~30 to 130 W·(m·K) −1 ], excellent thermal shock resistance, moderate density (6.10 g/cm 3 ), and chemical inertness against molten metals or nonbasic slags . These properties have made ZrB 2 an excellent candidate for aerospace applications such as wing leading edges, air intake and nose tips of the next generation of hypersonic scramjets and aerospace vehicles . Nevertheless, ZrB 2 exhibits poor sinterability due to the strong covalent bonding and low self‐diffusion coefficients.…”

“…12,13 These properties have made ZrB 2 an excellent candidate for aerospace applications such as wing leading edges, air intake and nose tips of the next generation of hypersonic scramjets and aerospace vehicles. [14][15][16] Nevertheless, ZrB 2 exhibits poor sinterability due to the strong covalent bonding and low self-diffusion coefficients. As a result, hot pressing is usually required to reach high densities for zirconium diboride ceramics.…”