Nanohardness of Sintered and Shock Deformed Alumina

作者：Chakraborty Riya^*; Dey Arjun; Mukhopadhyay Anoop K; Joshi Keshaw D; Rav Amit; Mandal Ashok K; Bysakh Sandip; Biswas Sampad K; Gupta Satish C

来源：Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 2012, 43A(2): 459-470.

DOI：10.1007/s11661-011-0900-z

To understand how high-strain rate, flyer-plate impact affects the nanohardness of a coarse (similar to 10 mu m) grain, high-density (similar to 3.978 gm cc(-1)) alumina, load controlled nanoindentation experiments were conducted with a Berkovich indenter on as-sintered disks and shock-recovered alumina fragments obtained from an earlier flyer-plate shock impact study. The nanohardness of the shock-recovered alumina was much lower than that of the as-sintered alumina. The indentation size effect was severe in the shock-recovered alumina but only mild in the as-sintered alumina. Extensive additional characterization by field emission scanning electron microscopy, transmission electron microscopy, and analysis of the experimental load depth data were used to provide a new explanation for the presence of strong indentation size effect in the shock-recovered alumina. Finally, a qualitative model was proposed to provide a rationale for the whole scenario of nanoindentation responses in the as-sintered and shock-recovered alumina ceramics.

• 出版日期2012-2