Thermal Conductivity Of Silicon Nitride Ceramics

Dense silicon nitride si 3 n 4 ceramics were prepared using y 2 o 3 and mgf 2 as sintering aids by spark plasma sintering sps at 1650 c for 5 min and post sintering annealing at 1900 c for 4 h.

Thermal conductivity of silicon nitride ceramics. Silicon nitride si 3 n 4 with high thermal conductivity has emerged as one of the most promising substrate materials for the next generation power devices this paper gives an overview on recent developments in preparing high thermal conductivity si 3 n 4 by a sintering of reaction bonded silicon nitride srbsn method. Silicon nitride is a chemical compound of the elements silicon and nitrogen. Silicon nitride has the most versatile combination of mechanical thermal and electrical properties of any technical ceramic material. It is a high performance technical ceramic that is extremely hard and has exceptional thermal shock and impact resistance.

Silicon nitride si 3 n 4 composites containing carbon nanotubes cnts or graphene nanoplateles gnps are of great relevance in the electronic and aerospace industries where the search for new materials with enhanced and anisotropic thermal conductivity to work in harsh environments is a strategic guideline here we study thermal conduction in si 3 n 4 composites with different amounts of. The bonding strength average atomic mass and anharmonic vibration of silicon nitride ceramics are similar to those of sic. Because of the strong covalent nature of si n bond si 3 n 4 ceramics possess a lot of attractive properties such as high strength at room and elevated temperatures high hardness good resistance to corrosion thermal shock and oxidation and so on besides si 3 n 4 ceramics have gained a staunch reputation of high thermal conductivity since haggerty and lightfoot. Due to the reduction of lattice oxygen content the srbsn ceramics could.

Silicon nitride si 3 n 4 ceramic properties. Si 3 n 4 is the most thermodynamically stable of the silicon nitrides. The theoretical thermal conductivity of silicon nitride crystals is 200 320 w m k. The thermal conductivity of sn1 was about 55 w mk at 323 k and decreased as the temperature increased reaching 45 w mk at 473 k.

It is a white high melting point solid that is relatively chemically inert being attacked by dilute hf and hot h. Hence si 3 n 4 is the most commercially important of the silicon nitrides when referring to the term silicon nitride. Silicon nitride si3n4 with high thermal conductivity has emerged as one of the most promising substrate materials for the next generation power devices. Effects of mgf 2 contents on densification phase transformation microstructure mechanical properties and thermal conductivity of the si 3 n 4 ceramics before and after heat treatment were.