Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

Abstract

A nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.

Near-seamless joining of Cf/SiC composites using Y3Si2C2 via electric field-assisted sintering technique

“…Therefore, the use of as-synthesized Y 3 Si 2 C 2 as the initial joining layer was proposed in the present work to obtain the nearseamless C f /SiC joints. However, only a few works have been focused on the synthesis of Y 3 Si 2 C 2 [36,37]. Gerdes et al [36] used the arc-melting of the Y, Si, and C powder mixture, followed by its annealing at 900 ℃ in an evacuated silica tube furnace for 30 d. This approach was too demanding on time, thereby not cost-effective.…”

Low‐temperature Pr3Si2C2‐assisted liquid‐phase sintering of SiC with improved thermal conductivity

“…It has been the most popular liquid-phase sintering additive for SiC ever, as not only due to its relatively low eutectic temperature (∼1780 • C), but also for its contribution to the formation of an in situ toughened microstructure. 19,20 Recently, a new ternary-layered Y 3 Si 2 C 2 material was successfully used as the sintering additive for SiC and SiC/Al 4 SiC 4 multiphase ceramics, as it forms a liquid phase by the eutectic reaction with SiC at ∼1560 • C. [21][22][23][24] Almost fully dense SiC materials were obtained after sintering at 1700 • C.…”

The diffuse interface phase‐field model for in situ interlayer phase formations in low‐temperature reaction bonding of alumina laminates—A theoretical and experimental comparison

“…9 These chemical reactions led to partial dissociation of ceramic layers in laminates 10 and solution during heating and super saturation-precipitation during cooling processes. 11 High temperature-pressure bonding ensures completion of reaction at interface but causes destructive occurrence of diffuse out of elements, 12 isolated voids, 6 interface movement, 13 kirkendall porosities, 14 deleterious reaction products, and severe volume change during reaction and local stressfiges. 15 A new approach of improving bond quality 16 and even decreasing bonding pressure and temperature 17 can be based on simultaneous reduction of interlayer materials/adjacent ceramic interface 18 and formation of homogeneous bonding products 19 with minimum mismatch with ceramic laminates.…”