Enhanced thermal conductivity in Si₃N₄ ceramic with the addition of Y₂Si₄N₆C

Abstract

Si3N4 ceramic was densified at 1900°C for 12 hours under 1 MPa nitrogen pressure, using MgO and self‐synthesized Y2Si4N6C as sintering aids. The microstructures and thermal conductivity of as‐sintered bulk were systematically investigated, in comparison to the counterpart doped with Y2O3‐MgO additives. Y2Si4N6C addition induced a higher nitrogen/oxygen atomic ratio in the secondary phase by introducing nitrogen and promoting the elimination of SiO2, resulting in enlarged grains, reduced lattice oxygen content, increased Si3N4‐Si3N4 contiguity and more crystallized intergranular phase in the densified Si3N4 specimen. Consequently, the substitution of Y2O3 by Y2Si4N6C led to a great increase in ~30.4% in thermal conductivity from 92 to 120 W m−1 K−1 for Si3N4 ceramic.

A hierarchically encapsulated phase-change film with multi-stage heat management properties and conformable self-interfacing contacts for enhanced interface heat dissipation

“…S3, ESI†). 46 First, silane coupling agents (KH-570) were modified onto the surface of n -Si 3 N 4 particles (Fig. S4, ESI†) to build a “molecular bridge” between the interfaces of inorganic ceramic particles and organic substances, which could greatly reduce the agglomeration of n -Si 3 N 4 particles in the subsequent organic precursor system.…”

A novel method of strong and tough Si3N4 ceramic from the particle‐stabilized foam

“…Si 3 N 4 ceramics have excellent comprehensive properties, such as high strength, high hardness, wear resistance, oxidation resistance, thermal shock resistance, and chemical corrosion resistance, which is considered one of the most promising industrial structural ceramics. [1][2][3][4][5] However, the inherent brittleness of Si 3 N 4 ceramics also limits the reliability of applications where brittle fractures occur at the crack propagation, resulting in catastrophic damage. Therefore, improving the fracture toughness of Si 3 N 4 ceramics remains one of the most critical issues.…”

Granulation of Silicon Nitride Powders by Spray Drying: A Review

“…Besides, MgO, Al 2 O 3 , and Y 2 O 3 are used to form phases such as SiAlON, MgSiO 4 , and MgSiO 3 [ 37 , 38 ]. In addition to the listed materials, other additives such as MgSiN 2 , YbF 3 , and Y 2 Si 4 N 6 C have been proposed to increase the nitrogen/oxygen ratio [ 33 , 39 ]. Furthermore, Tatami et al [ 40 ] reported that a joint addition of AlN and TiO 2 with sintering aids resulting in TiN microstructures in Si 3 N 4 ceramics improves the fracture toughness the sintered ceramics.…”