Machining damage in lead zirconate titanate ceramics
Professor Roger Whatmore and Dr Christopher Goat
Cranfield University
Ferroelectric ceramics, particularly those based upon the lead
zirconate titanate (PZT) solid solution system, offer a range of properties
which are widely used, particularly the pyroelectric effect for thermal
infra-red detection and imaging and the piezoelectric effect for sensors
(sound, acceleration, etc), and for actuators (motors, pumps, ink jet
printers, etc). Many of these devices are based upon bulk ceramic
materials which are shaped using single or multi-point machining processes
such as diamond turning, grinding or lapping/polishing. In all cases, the
materials exhibit ferroelastic characteristics as a natural adjunct to the
ferroelectric properties which make them of such great technological
interest. This means that the stresses involved in the machining process
will move domain walls within the grains and thus there is an effect upon
the polarisation of the ceramic and hence the final device performance.
This talk will review recent work upon the processes of electrical and
mechanical damage in both undoped and doped PZT ceramics at Cranfield
University and discuss the correlation of the damage processes with ceramic
composition.
