Alumina ceramics fabricated from bimodal alumina with additives

Fabrication of porous alumina ceramics from powder mixtures with sol–gel derived nanometer alumina: Effect of mixing method

“…Although there was no explanation for the density decrease, the strength increase was attributed to the growth of interparticle contacts due to the high diffusion rate of the nanoparticles accumulated in the grain boundaries. Li et al 5 have also observed lower density in samples sintered at low temperature (1400 • C) when they added superfine ␣-alumina (10-30 wt%) to a commercial submicrometer sized ␣-alumina containing MgO and SiO 2 additives. They attributed this behaviour to porosity located among small grains which cannot be removed by rearrangement and solid state sintering.…”

“…In order to substantially increase the strength keeping high porosity, very promising approaches are the mixing of materials with different particle size distributions and the addition of nanoparticles. 3,5,[11][12][13] Thus, ceramics with improved mechanical properties and precisely controlled pore-structural * Corresponding author. Tel.…”

“…characteristics have been developed by using bimodal powder consisting of coarse and very fine particles, 3,5,11,12 whereas many researchers are also investigating the effect of bimodal powder mixtures on final ceramic microstructure. 4,6,7 The basic assumption made is that the use of such mixtures results to better particle packing, more homogeneous microstructures, enhanced surface and grain boundary diffusion at intermediate temperatures and retarded densification at high temperatures.…”

Enhanced properties of alumina–aluminium titanate composites obtained by spark plasma reaction-sintering of slip cast green bodies

“…The properties of Al2O3-based ceramics strongly depend on the final microstructure, which is undoubtedly attached with the characteristics (size, shape, chemistry, etc.) of the starting powders [10]. In general, Al2TiO5 is formed by the solid-state reaction between Al2O3 and TiO2 (T), which is thermodynamically possible above the eutectoid temperature 1280 ºC [11].…”

In situ alumina/aluminum titanate bulk ceramic composites prepared by SPS from different structured composite powders

“…The properties of Al 2 O 3 -based ceramics depend much on the final microstructures which are inseparably influenced by the characteristics (size, shape, chemistry, etc.) of the starting powders [24] composite can be fabricated by sol-gel processing, directional solidification, combusting, powder metallurgy processing, hot pressing, etc. [14,[25][26][27].…”