Effects of NiO Nanoparticles on Physical and Mechanical Properties of BNKT Lead-Free Ceramics

摘要

In this research, The effects of NiO nanoparticles on the physical and mechanical properties of Bi_(0.5)(Na_(0.81)K_(0.19))_(0.5)TiO_3 (BNKT) were investigated. The ceramics were synthesized by solid state reaction technique. The powder of BNKT was calcined at 850°C for 4 h. The ceramics of BNKT/x vol.% NiO (i.e. x= 0.0, 1.0, 2.0 and 3.0) were sintered at 1000-1150°C for 2 h for optimize condition. Densification, phase formation, microstructure and micro hardness of samples were characterized via Archimedes method, X-ray diffraction techniques (XRD), scanning electron microscope (SEM) and Vickers micro hardness tester. The X-ray diffraction analysis of the ceramics suggests that all samples exhibited a perovskite structure. Densification of samples tended to increase with increasing amount of NiO content with maximum (5.73 g/cm~3) at 1.0 vol.% NiO additive. The NiO additive influenced densification as well as the mechanical properties of the samples. The addition of a small amount of NiO increased the Vicker hardness, Young's modulus and fracture toughness up to 6.17 GPa, 135 GPa, and 1.7 MPa m~(1/2), respectively while the grain size decreased down to 3.25 μm for 1.0 vol.% NiO additive. The results of this research suggest that NiO nanoparticles have an influence on physical and mechanical properties of BNKT ceramics.