Effect of hexagonal BN on the microstructure and mechanical properties of Si3N4 ceramics

Friction and wear properties of nano-Si3N4/nano-SiC composite under nanolubricated conditions

“…The method of preparation included the formation of silicon carbide nanograins using the carbothermal reduction of SiO 2 by carbon in the Y 2 O 3 -SiO 2 system at sintering temperature [6,25,26]. The hardness and density of the nano-Si 3 N 4 / nano-SiC composite were 17 GPa and 3.06 g/cm 3 , respectively. The disc was polished at a uniform pressure of 2.5 MPa by 5 µm diamond paste, resulting in the mirror polished finish of the disc before the actual tribological tests were performed.…”

“…It is well known that ceramics experience severe wear damage and high friction during unlubricated sliding contact, especially under conditions of high load, speed, and temperature [2]. Compared with other ceramic composites, nano-Si 3 N 4 composites possess higher hardness and high wear resistance [1][2][3]. However, their poor frictional properties restrict the use of such class of ceramics in engineering applications [2].…”

Investigation of the effect of ZrO2 and ZrO2/Al2O3 additions on the hot-pressing and properties of equimolecular mixtures of α- and β-Si3N4

“…In addition, the brittleness of silicon nitride is considered one of its main drawbacks that limit its application. However, many approaches have been proposed to improve the fracture toughness of Si 3 N 4 [13][14][15][16][17].…”

“…The a-Si 3 N 4 , particles dissolve in the liquid and precipitate as b-Si 3 N 4 , via a reconstructive phase transformation. While sintering continues, the b-Si 3 N 4 , nuclei grow as elongated grains and form an interlocked grain structure [9,15,16,18,24,[27][28][29][30][31][32][33][34][35][36][37][38]. It has been noted that fully dense objects cannot be produced without the use of sintering additives.…”

“…It has been noted that fully dense objects cannot be produced without the use of sintering additives. As previously mentioned, the type and amount of sintering additives determine the nature and the properties of liquid formed [9,15,16,18,23,[27][28][29][30][31][32]. Al 2 O 3 , Y 2 O 3 , MgO, AlN as well as rare earth oxides have been used as sintering additives for silicon nitride.…”