High thermal conductivity of spark plasma sintered silicon carbide ceramics with yttria and scandia

Abstract

A fully dense SiC ceramic with a room-temperature thermal conductivity of 262 WÁ(mÁK) À1 was obtained via spark plasma sintering b-SiC powder containing 0.79 vol% Y 2 O 3 -Sc 2 O 3 . High-resolution transmission electron microscopy revealed two different SiC-SiC boundaries, that is, amorphous and clean boundaries, in addition to a fully crystallized junction phase. A high thermal conductivity was attributed to a low lattice oxygen content and the presence of clean SiC-SiC boundaries. K E Y W O R D S silicon carbide, spark plasma sintering, thermal conductivity

Preliminary study of sintering zero‐rupture Fully Ceramic Microencapsulated (FCM) fuel

“…The diffusion and grain coarsening, using data derived from prior work, 1 are the major mechanisms during the sintering process, and are mainly governed by and correlated well with the temperature for TEP SiC. 11,18 So, the temperature gradient in the pellet seems to be the primary cause of the density variation within the pellet.…”

“…Riedel's model 9 was used to model the sintering process. 11,18 So, the temperature gradient in the pellet seems to be the primary cause of the density variation within the pellet. The model considers the physical mechanisms such as diffusion and grain coarsening during the sintering process.…”

Effect of additive content on the mechanical and thermal properties of pressureless liquid-phase sintered SiC

“…Thus far, extensive research has been conducted on the effect of additive chemistry on microstructure and the various properties of the SiC ceramics. In fact, the microstructure and mechanical, thermal, and electrical properties of the SiC ceramics can be tuned by adjusting the chemistry of the sintering additives [2,[9][10][11][12][13][14][15]. For example, SiC ceramics exhibited a high fracture toughness (8.4 MPaˑm 1/2 ) when sintered with Al 2 O 3 -Y 2 O 3 -CaO [10], high flexural strength (1077 GPa) when sintered with Y 2 O 3 -Sc 2 O 3 -MgO [11], high thermal conductivity (262 Wm −1 K −1 ) when sintered with Y 2 O 3 -Sc 2 O 3 [12], high electrical conductivity (6.7 × 10 3 Ω −1 ˑcm −1 ) when sintered with Y 2 O 3 -Lu 2 O 3 [13], high electrical resistivity (~10 13 Ωˑcm) when sintered with Al 2 O 3 -AlN-Y 2 O 3 [14], and high flexural strength (~600 MPa) at an elevated temperature (1600°C) when sintered with AlN-Lu 2 O 3 [15].…”

Joining of silicon carbide ceramics using a silicon carbide tape

“…Silicon carbide (SiC) ceramics and SiC‐based composites are being developed or are already used in a wide variety of structural applications at room and high temperatures because of their favorable properties including high thermal conductivity, good neutron irradiation resistance, excellent high‐temperature mechanical properties, and good resistance to wear, oxidation, and corrosion . Current and potential applications of SiC ceramics and SiC‐based composites include armor plates, mechanical seals, semiconductor processing parts, micro‐electro‐mechanical systems, nuclear components, optical mirrors, and gas turbine engines .…”