Ultrahigh Density α-Al2O3 Ceramics Produced By Slip Casting

6. International Conference on Mathematics, Engineering, Natural Medical Sciences, (EJONS 6), Adana, Türkiye, 8 - 10 Mart 2019, cilt.1, ss.585-594

Aluminum oxide (α-Al2O3) is one of the most used compounds in various chemical, industrial

commercial applications and engineering processes because of its high melting point; low

electric and thermal conductivity; high elastic modulus and hardness; and excellent resistance

to the attack of strong inorganic acids. Slip casting is a process used to consolidate ceramic

powders into sophisticated shapes with high green densities. Currently it is used mainly for the

production of large components or for those having thin walls or a shell of complicated contours

where the costs involved preclude the use of other techniques such as die pressing or isostatic

pressing. In the production of Al2O3 crucibles, slip casting is a process that is both economical

and short-term. The aim of the present work was to identify the conditions for the preparation

of stable Al2O3 slurries with high solids content for the production of slip-cast parts with

improved properties, as well as to correlate the slurry properties to the final part properties. The

physical properties such as porosity, water absorption, bulk density, shrinkage properties and

thermal conductivity of sintered samples were investigated. The sintering behavior, surface

morphology, elemental distribution, bond structure and phase evaluation of the composite

ceramics were evaluated by Field emission scanning electron microscope, Energy-dispersive

X-ray spectroscopy, Fourier-transform infrared spectroscopy and X-ray diffraction

respectively. As a result, Al2O3 ceramics with high density-low porosity degree and with

smooth inner surfaces properties have been successfully produced.

Keywords: Ceramics, Slip casting, α-Al2O3, Sintering