Nanoindentation of shock deformed alumina

In the current study, the experimental results on the nanoindentation response of both as prepared and shock recovered alumina of 10 μm grain size and identical processing history are presented and analyzed. The shock recovery experiments were deliberately conducted with gas gun arrangements at shock pressures much above the Hugoniot Elastic Limit (HEL) of alumina. The nanoindentation experiments were conducted at 10–1000 mN load with a Berkovich indenter. The nanohardness and Youngʹs modulus value of shock recovered alumina were always lower than those of the as prepared alumina samples. Subsequently, the detailed characterizations of the shock recovered alumina samples by X-ray diffraction, scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were utilized to understand the reasons behind the drop in nanohardness and Youngʹs modulus of shock recovered alumina samples.