R-curve behavior and flexural strength of zirconia-toughened alumina and partially stabilized zirconia composite laminates

Journal
Ceramics international  
Volume
44
Issue
12
Start Page
13463
End Page
13468
Citation
Ceramics International 12 (44): 13463-13468 (2018-08-15)
Publisher DOI
10.1016/j.ceramint.2018.04.107
Scopus ID
2-s2.0-85046852262
A composite-laminate formed by thick layers ( 320 µm) of zirconia-toughened alumina (ZTA) with thin ( 50 µm) interlayers of zirconia partially stabilized (Y-PSZ) has been fabricated by tape casting and pressureless sintering. Fracture behavior and strength has been investigated and compared to a “monolithic” reference, e.g. a stack of zirconia-toughened alumina (ZTA) without interlayers. The fracture behavior has been analysed using stable crack growth in V-notched specimens loaded in 3-point bending. The ZTA+Y-PSZ composite laminate presented a rising crack resistance with maximum values between 6 and 14 MPa m1/2. In contrast, the “monolithic” ZTA laminate shows a plateau R-curve behavior at 2.7 MPa m1/2. Several toughening mechanisms were identified in the ZTA+Y-PSZ composite laminate, such as, crack arrest/slow down, micro cracking and bifurcation. These toughening mechanisms are most likely caused by high tensile residual stresses that were estimated theoretically.