Mechanical Properties of (CuTl)-1223 Substituted by Pr.

CuTlBaCaPrCuO superconducting samples, with 0≤ x≤0.15, were prepared by a single-step solid state reaction on a form of rectangular bar. The prepared samples were characterized using X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The room temperature Vickers microhardness was measured at different loads (0.25-3 N). The experimental results were analyzed using Meyer's law, Hays-Kendall approach, elastic/plastic deformation model, proportional specimen resistance model, and the indentation-induced cracking (IIC) model. Surprising results were obtained and showed that all samples in the form of rectangular bars exhibited reverse indentation size effect in contrary with those in the form of discs. Vickers microhardness values were decreased as Pr-content increased that consisting with the porosity results. Furthermore, the Young's modulus was determined using the dynamic resonance technique. A relation between Young's modulus ( E) and Vickers microhardness ( H) was obtained. [ABSTRACT FROM AUTHOR]