Synthesis of modified PbTiO3 powders and fibers by a liquid mix process

Modified PbTiO3 powders and fibers were fabricated using a liquid mix process. The processing parameters, such as calcinations temperature, ball milling conditions, and sintering temperature were correlated to the degree of powder aggregation, phase development, density, grain size, and microstructure uniformity. Results indicated that the degree of aggregation was strongly dependent on the calcinations temperature, and less dependent on the milling solvent and pH values. Powder with an extremely small particle size (similar to0.1-0.2 mum) and the desired perovskite structure, was obtained by calcining the precursor resin at 450 degreesC. Powder compacts made from this powder were sintered to nearly full density at 1200 degreesC with a uniform microstructure. Through proper control of the theological properties of the precursor by addition of small amount of polyacrylic acid, continuous precursor fibers were drawn. Oxide fibers were synthesized by subjecting the precursor fibers to a two-step heat treatment schedule at 600 degreesC in N-2 and air. Both hollow and solid fibers were pulled from the precursor mixture. The strength of the fibers was high enough to be handled but not high enough to enable the fabrication of a 1-3 composite structure. Further improvement of the control over processing parameters will be required to synthesize fibers for such use. However, the feasibility of using a liquid mix process for fabricating these fibers was established. (C) 2002 Elsevier Science B.V. All rights reserved.