Effect of cyclic loading on the microstructure of thin zirconia tapes

Abstract

The effect of cyclic loading on the microstructure and the phase composition of thin zirconia tapes was studied. Zirconium oxide stabilized with 3 mol% of yttrium was used for preparing the tapes by the gel-tape casting method. The static and cyclic strengths of the samples with a thickness of approximately 0.2 mm were tested. The average static strength of 1233 MPa was determined in a three-point bend configuration. The maximal flexural stress during cyclic loading had to be kept below 900 MPa to ensure the failure-free performance of the tapes - (107 cycles). No evidence of an excessive transformation of the tetragonal microstructure induced by cyclic loading was found. The transformation toughening mechanism of the tetragonal microstructure was not significantly affected by cyclic loading. Based on the results, thin flexible 3Y-TZP parts possess a low risk of mechanically induced excessive transformational microstructural changes during the service life of the part.