Synthesis and Characterization of BaTiO3-Based Foams with a Controlled Microstructure

Volume 6 Issue 6, Pages 651 – 660

Laurel Wucherer, Juan C. Nino, Francesco Basoli, Enrico Traversa
Published
Online: Oct 29 2008 1:05PM

DOI: 10.1111/j.1744-7402.2008.02303.x

ABSTRACT
BaTiO₃ foams were synthesized via the direct
foaming method using commercial powders. In order to control the
microstructure and by extension the properties, synthesis parameters
such as foaming agent, composition, sintering time, and sintering
temperature were varied to determine their influence. The effect of each
parameter on the microstructure was measured and characterized using
scanning electron microscopy, image analysis, helium pycnometry, and
mercury porosimetry. Microstructure was classified in terms of strut
characteristics, average grain size, average cell window size, porosity,
and grain boundary integrity. For example, foams with 30% ceramic
volume were synthesized using a laboratory-developed and a commercial
polyurethane (PU) system, both silicon (Si) free. When sintered at
1400°C for 8 h, they produced thick, dense struts and uniform pore-size
distributions, although with different characteristics. The foam
prepared with the laboratory-synthesized PU had a porosity of 90%, an
average grain size of 44.4 μm, and an average cell window size of
66.7 μm, while the foam prepared with the commercial PU had a porosity
of 87%, an average grain size of 20 μm, and an average cell window size
of 99 μm.

Online Access to Journal of Applied Ceramic Technology