Browsing by Author "Navarro, A."

Now showing 1 - 5 of 5
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    Aqueous colloidal processing and green sheet properties of lead zirconate titanate (PZT) ceramics made by tape casting
    (Elsevier Science B.V., Amsterdam., 2004-01-01T00:00:00Z) Navarro, A.; Alcock, Jeffrey R.; Whatmore, Roger W.
    An aqueous system for tape casting PZT ceramics was developed using poly (vinyl alcohol) binder, poly (propylene glycol) plasticizer, D3021 dispersant and Surfynol SE-F wetting agent. Screening experiments were performed to assess the stability of the suspension in the presence of the dispersant by performing pH, conductivity and Zeta potential measurements. Viscosity measurements were used to find the optimum level of dispersant needed to produce a stable slip at pH 10.2. Subsequently, the rheological and mechanical characteristics were also investigated.
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    Correlation of sintered microstructure with green density in thick film PZT
    (Trans Tech Publications, 2003-06-28T00:00:00Z) Mortara, L.; Navarro, A.; Whatmore, Roger W.; Alcock, Jeffrey R.
    High density and low grain size are essential for the production of thick-film ceramics, in order that they possess adequate strength for any subsequent processing steps. In this paper sintered density and grain size were studied as function of green density and firing temperature. Wafers possessing a higher green density showed a more homogeneous microstructure and a higher sintered density.
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    Fabrication of lead zirconate titanate ceramics for pyroelectric applications
    (Cranfield University, 2001-10) Navarro, A.; Whatmore, Roger W.; Alcock, Jeffrey R.
    The objective of this work was twofold, i.e. to develop an aqueous route for tape casting Lead Ziconate Titanate (PZT)ceramics for pyroelectric applications and to optimise the die-pressing route for reducing defect size and number in bulk Lead Zicronate Titanate ceramics (PZT).
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    New Advances in Forming Functional Ceramics for Micro Devices
    (2006-10-10T00:00:00Z) Dorey, Robert A.; Rocks, Sophie A.; Dauchy, Florent; Navarro, A.
    Micro electromechanical systems (MEMS) are finding uses in an increasing number of diverse applications. Currently the fabrication techniques used to produce such MEMS devices are primarily based on 2-D processing of thin films. The challenges faced by producing more complex structures (e.g. high aspect ratio, spans, and multi-material structures) require the development of new processing techniques. Potential solutions to these challenges based on low temperature processing of functional ceramics, selective chemical patterning, and micro-moulding are presented to show that it is possible to create complex functional ceramic structures which incorporate non-ceramic conducting and support structures. The capabilities of both techniques are compared and the relative advantages of each explored.
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    Steps towards ceramic process scale-up: analysis of a laboratory process
    (Elsevier Science B.V., Amsterdam., 2004-01-01T00:00:00Z) Mortara, L.; Navarro, A.; Whatmore, Roger W.; Alcock, Jeffrey R.
    In this paper the first steps towards a scaling up of a ceramic process are described, using as case study a lab-scale process, in which PZT ceramics are produced via an aqueous tape casting route. The process, the result of a feasibility study, was firstly analysed by drawing flowcharts; potential problems and flow bottlenecks were then identified and their solutions were pursued using a "soft" problem solving approach.