Al2O3 Ceramics with Graded Porosity Produced from Natural and Artificial Pore Formers

Year 2017, Volume: 20 Issue: 3, 595 - 598, 15.09.2017

Gülsüm Topateş

Abstract

Al₂O₃
ceramics with graded porosity were produced by using corn starch and PMMA
sphere as pore former additives (PFA). Graded porosity was obtained by
uniaxially pressing the stacks of Al₂O₃ mixtures with and
without PFA together. Pressed samples were heat-treated to remove PFAs at 600^oC
and sintered at 1540^oC. Final porosity of graded ceramics produced
from starch and PMMA were measured as 12 and 16%, obtained median pore size
were 3 and 11 µm, respectively. The elastic moduli of the samples were measured
by pulse-echo method and results showed that moduli values of the samples
varied significantly depending on the PFA type. PMMA added samples had lower
elastic moduli values than starch added ceramics as a result of higher pore
size and interconnected pore structure. By using the pulse-echo method, the
elastic properties of the graded samples couldn’t be measured effectively.

Keywords

Graded porosity, alumina, pore former

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