High-temperature strength of zirconia and its sensitivity to surface defects. (12th April 2019)

• Record Type: Journal Article
• Authors: Li, Dingyu; Li, Weiguo; Wang, Ruzhuan; Kou, Haibo
• Is Part Of: Materials research express. Volume 6:Number 7(2019)
• Publication Date: 2019-04-12
• Subjects: zirconia -- failure -- toughness and toughening -- strength; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/ab1525
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Flexural strength, fracture behavior and sensitivity to surface damage of ZrO2 ceramic were investigated by using specimens with and without surface scratch by three-point bending test at elevated temperatures ranging from room temperature to 1400 °C. The results of flexural strength as function of temperature showed the influence of surface defects on flexural strength weakened as the temperature increased. Flexural strength of the intact specimen decreased with increasing temperature. However, the flexural strength of the specimens with surface scratch first decreased from approximately 190 MPa at room temperature to approximately 60 MPa at 900 °C, increased as the temperature is increased to 1200 °C, and then decreased again at temperatures greater than 1200 °C. Furthermore, the sensitivity of strength to surface scratch was analyzed by using the ratio of the average flexural strength of the specimens with surface scratch to the average flexural strength of the intact specimens. Results indicated that the phase transition significantly affected the flexural strength and the sensitivity of the flexural strength to surface damage at temperature approximately 1170 °C. Moreover, above the phase transition temperature, the sensitivity of strength to surface damage decreased significantly.