Evaluation of stiffness constant c11 and meyer index of biomaterials prosopis juliflora and casuarina equisetifolia

Vickers and Knoop micro hardness tests were carried out on the pressed pellet form of Prosopis juliflora and Casuarina equisetifolia biomaterials subjected to a load range of 25–100g. Vickers (Hv) micro hardness for the above loads was found to be in the range of 29–57 kg/mm2 and 107-136 kg/mm2, for P.juliflora and C.equisetifolia respectively. Knoop (Hk) micro hardness number was found to be in the range 22–51 kg/mm2 and 82-127kg/mm2, for P.juliflora and C.equisetifolia respectively. Vickersmicrohardness number (Hv) and Knoop micro hardness number (Hk) was found to increase withincreasing load for both materials. Yield strength(σv) was calculated using Hv. Meyer’s index number (n) calculated from Hv shows that the materials belonging to the soft material category. Using Wooster’s empirical relation, the elastic stiffness constant (C11) was calculated from Vickers hardnessvalues. Young’s modulus was calculated using Knoop hardness values. Our study reveals that C.equisetifolia having high modulus of elasticity than P.juliflora.