Authors: Suresh Sagadevan, R. Varatharajan
The microhardness study reveals the mechanical strength of the grown crystal. The Vicker’s and Knoop hardness studies were performed to understand the mechanical behavior of the glycine lithium chloride crystals. The Vicker’s and Knoop microhardness numbers (HV and HK) for the crystal were found for different loads. It is found that these numbers increase with an increase in the load. The Mayer’s index (n) was found to be greater than 1.6 predicting a soft-material nature. The fracture toughness value (Kc), was determined from the measurements of the crack length. The brittleness indices (Bi) were found for the grown crystals. Using Wooster’s empirical relation, the elastic stiffness constant (C11) was calculated from the Vicker’s hardness values at different loads. The Young’s modulus was also calculated from Knoop microhardness values. Key words: Microhardness number, Mayer’s index, fracture toughness, brittleness indices, elastic stiffness coefficient, Young’s modulus.