Experimental and theoretical modelling of Vickers, Knoop microhardness and laser damage threshold studies on Ca0.9Nd0.1Ti0.9Al0.1O3 single crystals grown by optical floating zone technique

Abstract

Vickers and Knoop microhardness studies were done on the (200) face of Ca0.9Nd0.1Ti0.9Al0.1O3 crystals grown by optical floating zone technique for various loads ranging from to 0.24–9.8 N. Various important mechanical properties such as Vickers hardness, Knoop hardness, Young's (elastic) modulus, yield strength, stiffness constant which accounts for various industrial applications were determined. The Indentation Size Effect (ISE) were observed for the grown crystal, four different models such as Meyer's law, Hays-Kendall (HK) model, proportional sample resistance (PSR) model, elastic/plastic deformation model (EPD) were used to determine the true hardness values. Among these four mechanical analysis models, HK approach seemed to be the best model to describe the mechanical properties of the grown crystal. The variation of microhardness number for different orientations showed the presence of microhardness anisotropy in the grown crystal. Laser damage threshold for the grown crystal was found to be 2.49 GWm−2.