Single Crystal Piezoelectric Ceramic Production Research

DMTC research partners are working with Thales to investigate single crystal growth technologies that could guarantee the in-country supply of the base materials required to produce high performance ceramic sonar. An extensive literature review revealed several competing technologies were available for the preparation of lead based formulations. Laboratory scale trials have been conducted at the Institute of Semiconductor and Electronic Materials (ISEM) labs at the University of Wollongong and at the Institute of Materials Engineering at ANSTO to assess melt growth (Bridgeman method) and solid state conversion of piezoceramic compositions.

The research team at ISEM Wollongong have investigated modified flux growth methods that create a liquid solidification interface using a gradient profiled furnace to grow lead based crystals. A large body of work focused on alternate containment materials to platinum to ensure that a cost effective process can be developed.

ANSTO’s project team have evaluated the narrow process window of crystals grown by solid state methods and have mapped this process window to allow both seed-crystals and piezoelectric elements and components to be reproducible. ANSTO has also investigated ceramic tape technology to develop as a near net shaped component. The process involves sintering a thin large area polycrystalline matrix to full density followed by a prescribed annealing step.

This preliminary project has just been completed and a subsequent stage of research is anticipated to be funded in 2015 to develop the technologies for scaled-up production capability.

Posted by DMTC on August 11th, 2014