Effect of Barium Addition on Some Mechanical Properties Deduced from Vickers Hardness Tests of Bi-2212 Ceramics

Authors : Ali Mercan, Tahsin Turgay, Muhammed Öz, Gürcan Yildirim

Pages : 56-65

Doi:10.29137/umagd.1372306

View : 47 | Download : 48

Publication Date : 2024-01-31

Article Type : Research Paper

Abstract :In this study, the variations of the basic mechanical performance properties (microhardness (Hv), elastic modulus, hardness shear modulus, brittleness index, yield strength, elastic hardness coefficient, fracture toughness, ductility, flexibility and durability) of new Bi2.1-xBaxSr2.0Ca1.1Cu2.0Oy (Bi-2212) superconducting materials produced by doping different amounts (ranging from 0.0≤x≤0.1) of barium ions into the crystal matrix of Bi-2212 superconducting material were investigated in detail by microindentation Vickers hardness (Hv) tests in the applied load range 0.245N-2.940 N. In addition, the change of resistance to crack propagation, durable tetragonal phase, mechanical efficiency and mechanical characteristics of the Bi-2212 ceramic system with Ba/Bi partial substitution in the crystal structure was determined. According to experimental and theoretical findings, the overall mechanical performance of the Bi-2212 superconducting crystal structure increased significantly up to the Ba/Bi replacement level of x=0.01, while a systematic reduction was observed after this substitution ratio. Furthermore, the optimum presence of barium in the crystal lattice let to the formation of new slip systems within the structure, new bond formations between atoms, reduction of stress regions on the surface and rise at strength and fracture toughness. Besides, the optimum level resulted in improved material crystal quality and intergranular bonding. When the mechanical characteristic behavior was examined, it was found that all materials presented the typical indentation size effect (ISE) characteristic and there was a significant improvement in ISE characteristic at the optimum replacement ratio.
Keywords : Bi 2212 kristal sistem, Ba Bi yer değiştirme, Kayma sistemleri, Hv, ÇBE