Tensile behavior of tetragonal zirconia micro/nano‐fibers and beams in situ tested by push‐to‐pull devices

• Published in: Journal of the American Ceramic Society 2022-09, Vol.105 (9), p.5911-5920
• Main Authors: Zeng, Xiao Mei, Ye, Pengcheng, Tan, Hui Teng, Du, Zehui, Gan, Chee Lip
• Format: Article
• Language: English
• Subjects: Ceramics; Compressive strength; Crystal structure; Elastic deformation; Fibers; fracture; Martensitic transformations; Mechanical properties; microstructure; Nanoindenters; Shape memory; Tensile strength; tension test; Tetragonal zirconia
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.18555

The tensile mechanical behavior of tetragonal zirconia micro/nano‐fibers and beams was studied with push‐to‐pull (PTP) devices equipped in an in situ nanoindenter. The small‐volume ceramics generally experienced linear elastic deformation before fracture. Polycrystalline and oligocrystalline micro/nano‐fibers exhibit a tensile strength of ∼0.9–1.4 GPa, while single‐crystal beams exhibit a much higher tensile strength (∼2.1–3.2 GPa). The tensile strength of the small‐volume zirconia is found comparable to the corresponding compressive strength, which indicates the large discrepancy between the tensile and compressive strength observed in bulk zirconia becomes insignificant at micro/nano‐scales. No martensitic transformation induced shape memory strain was detected in the zirconia fibers and beams. Further variation in dopant concentration and crystal orientation was explored for single‐crystal beams and their significance in controlling the tensile strength was discussed. Our work offers a new insight into the mechanical behavior of tetragonal zirconia‐based ceramics at small scales. The tetragonal zirconia micro/nano‐fibers and beams with polycrystalline, oligocrystalline or single crystal structures generally experienced linear elastic deformation before fracture when subject to tensile stress, and no martensitic transformation induced shape memory strain was detected. The tensile strength is varied in ∼0.9‐3.2 GPa and is comparable to the corresponding compressive strength, which indicates the large discrepancy between the tensile and compressive strength observed in bulk ceramics is insignificant at micro/nano‐scales.