Preparation of Agglomerate-Free Starting Powders for TiC_p-Reinforced β-Sialon Nanocomposites

Abstract

By changing the molecular weight and concentration of dispersant, PH value of dispersion solution and treat process, this paper focuses on the optimization parameters of the TiCp-reinforced ß-sialon nanocomposites suspensions. Zeta potentials, sedimentation tests have been carried out to prepare a well reagglomerated and uniform suspensions. The optimum molecular weight of PEG is 1540 for Al2O3 powder and 4000 for others, while the concentration is 0.5wt% to 0.8wt% with the pH values range from 9.5 to 10. After addition of dispersant, PEG (polyethylene glycol), the surfaces of the TiC particles and Sialon contents were selectively covered with long organic molecular chains by soaking within solution. The resulting powders not only resisted reagglomeration, but were also readily dispersible within the mixed solution. Optimum dispersion conditions, i.e. the surfactant molecular weight and the concentration, the PH value of the suspens ions and the soaking time were determined.

The effect of the wet-milling process on sintering temperature and the amount of additive of SiAlON ceramics

“…The solvent compositions were determined according to literature studies [7][8][9][10][11][12]. The sedimentation method was used for determination of an adequate dispersion in order to use ball milling energy to decrease the particle size of the starting powders.…”

“…Thus, in an agglomerate-free system, energy will be transferred to the powder to decrease particle size. There are few studies [7][8][9][10] investigating well-dispersed suspension systems for SiAlON ceramics but these did not include any comparison between solvent and dispersant types. In this study, SiAlON powders milled in different solvent mediums (toluene, methyl ethyl ketone, and ethanol) with different kinds of dispersants (oleic acid, poly ethylene glicol, sodium tripolyphosphate) and sedimentation tests were performed.…”

Nano‐Hydroxyapatite Improves the Properties of β‐tricalcium Phosphate Bone Scaffolds

“…Therefore, it cannot be used for heavy load‐bearing applications. The addition of a particulate second phase to a ceramic matrix is well known as a method of achieving enhanced mechanical properties in the matrix . Lin et al .…”

The production of β-SiAlON ceramics with low amounts of additive, at low sintering temperature

“…However, only a few published papers relate the solvent and dispersant type to the well-dispersed suspension system in order to decrease the starting particle size. 4,[8][9][10] In our previous study we explain this relationship in the ␣-SiAlON materials. 11 However, there is no information relating to this in the ␤-SiAlON system.…”

“…[1][2][3][4][5] Previous studies show that it is possible to densify SiAlON ceramics at 1500 • C using plasma-chemical synthesized starting powders with a specific surface area of 65 m 2 /g. 1 However, plasma-chemical synthesis would increase the cost of the initial powder.…”