Bill Denne
Denne Research
Cambridge
Email DenneLabs@aol.com
Inclusion of a small amount (<.1%) of magnesium orthosilicate, Mg2SiO4, in the PZT mix stops PZT components sintering together during firing. The material is available from Alfa Aesar 99-800-4566-4566 but may require grinding to a finer powder before use.
2. 1200oC Cling film
Lead loss is a perennial concern in PZT firing. Coors supply 96% 1mm thick alumina plates for hybrid circuit substrates. In the presence of a minute amount of lead vapour at 1100oC +, these will reversibly sag under their own weight. If the top of the crucible is machined or lapped flat, a Coors 1mm alumina lid will also fit perfectly at temperature! CoorsTek 01592 773743 (Glenrothes, Fife)
3. Impossibly large flat thin PZT plates.
Tape cast green state PZT is easily made in large sheets. It may be fired between 1 mm Coors alumina plates (externally supported with flat firebrick) to provide large flat PZT plates. [200 mm x 50 mm x 0.5 mm flat to .001 mm per mm for example]
4. Impossible PZT slotting!
Tungsten wire wound on a grooved aluminium mandrel and electroless nickel plated in a diamond slurry provides a splendid tool for gang slitting PZT to impossible depths on ridiculously fine pitches!
