Single point diamond machining of ferroelectric materials

One of the most important ferroelectric ceramic materials used in a wide ra nge of applications is the lean zirconate titanate solid solution series (P ZT). The ability to machine ferroelectrics in a ductile manner and by so do ing reduce sub-surface damage, could eliminate the need for subsequent lapp ing and polishing and thus reduce production costs. Fracture mechanics tech niques were used to investigate the localised elastic/plastic behaviour in these materials. The possibility of machining brittle materials using singl e point diamond turning in a 'ductile mode' has been investigated by many r esearchers in recent years and for this study poled and unpoled PZT ceramic s were single point diamond turned tinder different machining conditions an d ductile machining has been achieved. X-ray diffraction (XRD) indicates th e degree of domain reorientation caused by machining, and it is suggested t hat the strain generated by re-orientation accounts for brittle damage. App ropriate poring can have a marked effect on the brittle/ductile machining r esponse. (C) 1999 Elsevier Science Limited. All rights reserved.