Nano-scale mechanical properties and behavior of pre-sintered zirconia

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• 作者：Abdur-Rasheed Alao ; Ling Yin ; ^{ling.yin@jcu.edu.au" class="auth_mail}
• 关键词：Pre-sintered zirconia ; Loading rate ; Material behavior ; Mechanical properties ; Nanoindentation ; In situ SPM
• 刊名：Journal of the Mechanical Behavior of Biomedical Materials
• 出版年：August 2014
• 年：2014
• 卷：36
• 期：Complete
• 页码：21-31
• 全文大小：12090 K

文摘

This paper reports on the mechanical properties and material behavior of pre-sintered zirconia using nanoindentation with in situ scanning probe microscopy. Indentation contact hardness, H_c, and Young壮s modulus, E, were measured at loading rates of 0.1–2 mN/s and 10 mN peak load to understand the loading rate effect on its properties. Indentation imprints were analyzed using in situ scanning probe imaging to understand the indentation mechanisms. The average measured contact hardness was 0.92–1.28 GPa, independent of the loading rate (ANOVA, p>0.05). Young壮s moduli showed a loading rate dependence, with average 61.25 GPa and a great deviation at a low loading rate of 0.1 mN/s, which was twice the average moduli at the loading rates of 0.5–2 mN/s. Extensive discontinuities and the largest maximum penetration, final and contact depths were also observed on the load–displacement curves at the lowest loading rate. These phenomena corresponded to microstructural compaction (pore closure and opening) and kink band formation, indicating the loading rate dependence for microstructural changes during nanoindentation. The in situ scanning probe images of indentation imprints show plastic deformation without fracture at all loading rates, compaction at the low loading rate and pore filling at the high loading rate. The mechanical behavior studied provides physical insight into the abrasive machining responses of pre-sintered zirconia using sharp diamond abrasives.