Single point diamond turning of ferroelectric materials

One of the most important ferroelectric ceramics materials used in a wide range of applications is the lead zirconate titanate solid solution series (PZT). The possibility of machining brittle materials using single point diamond turning in a 'ductile mode' has been investigated by many researchers in recent years. The ability to machine ferroelectrics in a ductile manner and by so doing reduce sub-surface damage, could eliminate the need for subsequent lapping and polishing and thus reduce production costs. Fracture mechanics techniques were used to investigate the localised elastic/plastic behaviour. PZT ceramics in the poled and unpoled state were single point diamond turned under different machining conditions and ductile machining has been achieved. X-ray diffraction indicates the degree of domain reorientation caused by machining, and it is suggested that the strain generated by reorientation accounts for brittle damage. Appropriate poling can have a marked effect on the brittle/ductile machining response^[1].