Synthesis and sintering of TiB2 and TiB2–TiC composite under high pressure

High-Pressure, High-Temperature Behavior of Silicon Carbide: A Review

“…It was found in [14] that the 3C cubic phase was stable at lower temperatures but became more stable with increased pressure, while the 6H phase was preferred at high temperatures (2300-2800 K), at least at pressures of 6.5 GPa and below. These findings were supported by observations in [17] at pressures below 3 GPa. The phase boundary marking the transition to 6H likely crosses the melting/decomposition line at high pressures [18,19], however, implying that 3C may be the more stable solid phase at higher-pressure conditions.…”

“…SiC was seen to decompose up to 8 GPa based on quench texture and composition [110], although the temperature of the decomposition was not directly measured. Similar results were found in [17,106] in a high-pressure high-temperature cell at 3 GPa without a direct temperature measurement, though the power-temperature relation indicated that the sample was above 2800 K. Incongruent melting was also observed in [109] up to~10 GPa. Decomposition was identified through a change in the resistivity of the sample as well as through Si and C diffraction signals upon quench.…”

“…The ambient pressure decomposition of SiC into solid C plus liquid Si begins at~2840 K in experiments [19] but is predicted to occur at higher temperatures of 3100 K in computations [104,105]. Prior to recent diamond-anvil cell work up to~80 GPa [18], explorations of high-pressure melting and decomposition have gone up to~10 GPa while heating to temperatures as high as 3500 K [17,[106][107][108][109][110]. Although confusion has arisen as to the nature of SiC melting at lower pressures, higher pressure studies indicate that 3C-SiC continues to decompose at high temperature, at least up to the transition to the rocksalt structure at~60 GPa.…”

Simultaneous Synthesis and Consolidation of Nanostructured MoSi2-NbSi2 Composite by High-Frequency Induction Heated Sintering and Its Mechanical Properties

“…Their properties provide a desirable combination of a high melting temperature, high modulus, good oxidation resistance in air, a relatively low density, 1) and the ability to undergo plastic deformation above 1200 o C. 2) Combined with good thermal and electric conductivities, these properties have led to the utilization of MoSi 2 as a heating element material in high-temperature furnaces operating in air up to approximately 1700 o C. 3,4) However, as in the case of many similar compounds, the current concern about these materials(MoSi 2 and NbSi 2 ) focuses on their low fracture toughness below the ductile-brittle transition temperature. [5][6][7] To improve the mechanical properties of these materials, the fabrication of a nanostructured material and composite material [8][9][10][11] have been found to be effective. As nanomaterials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid to their potential application.…”

Microstructures and Mechanical Properties of Hot-Pressed -Matrix Composites Reinforced with SiC and Particles

“…However, as in the case of many such compounds, the current concern about these materials focuses on their low fracture toughness below the ductile-brittle transition temperature [5,6]. To improve the mechanical properties of these materials, the addition of a second phase to form composites [7][8][9][10] has been found to be effective. Silicon nitride (Si 3 N 4 ) has a high thermal shock resistance, due to its low thermal expansion coefficient and good resistance to oxidation when compared to other structural materials [11][12][13].…”