Physical and Mechanical Properties of Bi₀_.5(Na₀_.81K₀_.19)₀_.5TiO₃Ceramic Modified by KNbO₃

Abstract

This research reports the physical and mechanical properties of (1-x) Bi 0.5 (Na 0.81 K 0.19 ) 0.5 TiO 3 -xKNbO 3 (x=0.00-0.06) ceramics. The Modified Bi 0 .5 (Na 0 .81 K 0 .19 ) 0.5 TiO 3 ceramics were synthesized by solid state reaction technique. The mixed oxides powders were calcined at 850 °C, 4 h and sintered at 1120 °C, 2 h to form pure phase perovskite and the optimum bulk density, respectively. The phase formation of the modified ceramic samples was determined by X-ray diffraction technique. All of the modified Bi 0 .5 (Na 0 .81 K 0 .19 ) 0.5 TiO 3 ceramics exhibited a single perovskite phase. The bulk densities of the modified ceramic samples were 5.41±0.27-5.75±0.28 g/cm 3 using the Archimedes’ method. The microstructure was revealed by the scanning electron microscope. The rectangular-like shape was found of all studied ceramics which had the grain size between 1.31±0.02-1.56±0.03 mm. The mechanical properties were studied by both Vickers and Knoop microhardness tester. The results are discussed in term of the relation among hardness properties, Young’s modulus, and fracture toughness.