The phase stabilities of plain and CuO-doped (up to 0.2 wt.%) coated 2.5 mo
l% Y-TZP ceramics, sintered at 1300 degreesC, were investigated by exposure
in hostile environments for periods of up to 2000 h. CuO additions signifi
cantly reduced the rate of tetragonal to monoclinic phase transformation co
mpared with that for undoped samples. In addition the mechanical properties
of the doped materials were better in all cases. Specimen sectioning, howe
ver, revealed that after 200 h even the samples with CuO had developed thin
, measurable monoclinic layers. Doping of Y-TZP ceramics with small amounts
of CuO is one method of reducing ageing degradation without sacrificing ot
her properties. (C) 2001 Elsevier Science Ltd and Techna S.r.l. All rights
reserved.