Novel (Zr, Ti)(C, N)–SiC ceramics via reactive hot-pressing at low temperature

Microstructures and Enhanced Mechanical Properties of (Zr, Ti)(C, N)-Based Nanocomposites Fabricated by Reactive Hot-Pressing at Low Temperature

“…Nevertheless, β -ZrSi was found in the Z50T20S sample at room temperature, and its (002) diffraction peak shifted from 48.5 to 49.5 compared to the PDF card (# 04-004-7165), as shown in Table 2 . The above phenomenon, combined with our previous study [ 10 ], indicates that Ti atoms dissolved into the β -ZrSi lattice to form a (Zr, Ti)Si solid solution (CrB-type) and inhibited the transition from the β to the α.…”

“…However, the first stage is still dominated by the reaction because of the low temperature. Therefore, TiC 0.5 N 0.5 reacts with Si at this stage based on our previous research [ 10 ], as shown in Equation (2). TiC 0.5 N 0.5 (s) + Si (s) → SiC (s) + TiSi 2 (s) + TiN (s) …”

“…β -ZrSi can dissolve in Ti-Si liquid to form the Zr–Ti–Si liquid phase. The carbon atoms in the ZrC matrix diffuse into the Zr–Ti–Si liquid phase as the temperature increases, forming SiC, ZrC 1−x , and TiC 1−x [ 10 ]. In the process of heat and pressure preservation, the TiN generated in the first stage and the ZrC 1−x and TiC 1−x in the second stage gradually dissolve into the ZrC and TiC 0.5 N 0.5 lattices and finally form (Zr, Ti)(C, N) and(Ti, Zr)(C, N) solid solutions (ss), as shown in Equation (3).…”

“…Table 3 exhibits the content of phases in sintered ceramics calculated by the image analysis method. We previously reported that only (Zr, Ti)(C, N), and SiC existed in ceramic sintered at 1700 °C when the ratio of ZrC to Si was 90.25: 5 (mol%) in the ZrC-TiC 0.5 N 0.5 -Si system [ 10 ]. Therefore, it can be inferred that β -ZrSi does not exist in the Z50T5S ceramic, which has a phase composition of (Zr, Ti)(C, N)-31.2 vol% (Ti, Zr)(C, N)-4.2 vol% SiC.…”

“…ZrC is also considered a potential material in the framework of the generation-IV nuclear energy system due to its excellent resistance to corrosion by fission products and low neutron absorption cross-section [ 7 , 8 , 9 ]. Introducing lattice defects, such as abundant grain boundaries and lattice distortions, can further enhance the radiation resistance of ceramics [ 10 ].…”