Microstructural evolution of Al2O3–SiC nanocomposites during spark plasma sintering

Ultrafine Al2O3–B4C composites consolidated by pulsed electric current sintering

“…TiB 2 addition to B 4 C has been reported to result in a higher fracture toughness [6]. The addition of TiC, TiB 2 , WC or SiC particles in an Al 2 O 3 matrix improve the fracture toughness, hardness, and strength for cutting tool applications [8][9][10][11][12]. The mechanical properties of Al 2 O 3 were successfully improved with addition of 5-20 vol.% of whisker like and shardlike shaped B 4 C particles [13].…”

Microstructural design for mechanical and electrical properties of spark plasma sintered Al2O3–SiC nanocomposites

“…The high heating rates conventionally used in SPS sintering technique play an important role in the evolution of the material microstructure. High sintering rates such as those used in this work promote lattice diffusion and/or grain boundary diffusion which are major densification mechanisms in the high-temperature regime rather than surface diffusion as a coarsening mechanism [15].…”

“…Besides the sintering temperature, the presence of SiC particles as second phase also plays an important role in the alumina grain size control. The beneficial effect of the addition of SiC on the refinement of the alumina matrix microstructure has been studied by different authors [15,20,22]. This effect can be clearly observed when TTp and THb materials are compared.…”

“…This technique can work at heating rates of the order of hundreds degrees per minute combined with the external pressure assistance, reaching high temperatures in a very short time [11,12]. This sintering technique is being profusely applied in the preparation of a wide range of composites, but only three scientific publications can be found dealing with SPS sintered Al 2 O 3 -SiC materials [13][14][15]. All of them were focused on the SiC particles positioning in the final composite.…”

In situ preparation of Al2O3–SiC nanocomposites via sol–gel method followed by pressureless sintering

“…For complex powders, it achieves ultra homogenous mixing of the several components on a molecular scale [15][16][17]. Al 2 O 3 -SiC nanocomposites have previously been fabricated by pressureless sintering, hot pressing or spark plasma sintering of the mixture of alumina and silicon carbide nanopowders [18][19][20]7]. Gustafsson et al [21] used a mixture of alumina powder and silicon carbide precursors to prepare Al 2 O 3 -SiC nanocomposites.…”