Preparation of BaZrO 3 powders by a spray-drying process
- PDF / 445,560 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 52 Downloads / 229 Views
I. Vandriessche and S. Hoste Department of Inorganic and Physical Chemistry, University Gent, Krijgslaan 281, B-9000 Gent, Belgium
J. Lecomte-Beckers Department of Metallurgy, University of Lie`ge, Sart Tilman B52, B-4000 Lie`ge, Belgium (Received 15 July 2002; accepted 18 February 2003)
The potential use of barium zirconate for the manufacture of corrosion-resistant substrates emphasizes the need for a simple, inexpensive, and easily scalable process to produce high-quality powders with well-controlled composition and properties. However, the classical solid-state preparation of barium zirconate leads to an inhomogeneous powder unsuitable for applications in highly corrosive environment. For this paper, the possibility to use the spray-drying technique for the preparation of BaZrO3 powders with a controlled size distribution and morphology was investigated. The influence of the nature and concentration of the precursor solution and the influence of the spray-drying step are discussed on the basis of x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dilatometric measurements. I. INTRODUCTION
II. EXPERIMENTAL
For the past few years, there has been growing interest in the synthesis of high-quality barium zirconate powder. The need for reactive, ultrafine, high-purity powders has triggered the development of soft chemistry processes.1–10 In fact, the potential use of barium zirconate for the manufacture of corrosion resistant substrates and artifacts11 (crucibles, high temperature construction elements) emphasizes the need for a simple, inexpensive and easily scalable process to produce high-quality powders with well-controlled composition and properties. For this paper, a novel method exploiting the advantages of the spray-drying process was investigated. The advantages of the use of spray drying to synthesize highquality ceramics are numerous. The spray-drying technique generally leads to the formation of spherical powder agglomerates through the drying of sprayed droplets,12 with better control of homogeneity, particle size, and particle-size distribution. Moreover, the reactivity of the obtained powder is also improved.13,14 Particular attention was paid to the influence of the type of barium and zirconium sources and the presence of an organic fuel (oxalic dihydrazide15) on the morphology, chemical composition, and sintering behavior of the as-obtained materials.
The experimental procedure involves several steps: preparation of the mixed precursor solutions of barium and zirconium, spray drying of the solutions, and calcination of the spray-dried powders followed by characterization of the end products.
a)
Address all correspondence to this author. e-mail: [email protected] J. Mater. Res., Vol. 18, No. 6, Jun 2003
http://journals.cambridge.org
Downloaded: 13 Mar 2015
A. Preparation of the precursor solutions
The precursor solutions were prepared from different barium and zirconium sources with 1:1 stoichiometry. Table I summarizes the compositions of the diff
Data Loading...
