Effect of Nano-Oxides Addition on the Mechanical Properties of (CuTl)-1223 Phase.

In this study, superconducting samples of type CuTlBaCaCuO,(CuTl)-1223, added by SnO and InO in nano-scale were prepared by a solid-state reaction technique. The concentrations of both SnO and InO were varied from 0.0 to 1.0 wt.% of the total sample's mass. The prepared samples were characterized using X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) for phase analysis and microstructure examination, respectively. The electrical resistivity of the prepared samples was measured by the conventional four-probe technique from room temperature down to the zero superconducting transition temperature ( T). An increase in T is observed up to x=0.6 wt.% for (SnO) CuTlBaCaCuO, followed by a systematic decrease with increasing nano-SnO addition for x>0.6 wt.%. While, for (InO) CuTlBaCaCuO the T is slightly changed with x. Room temperature Vickers microhardness measurements were carried out at different applied loads (0.49-2.94 N) for the study of the mechanical performance of the prepared samples and examination of the effect of different nano-oxides addition on the microhardness of (CuTl)-1223 phase. Furthermore, the true microhardness values ( H), for both additions, were evaluated through different models and their results were compared with those estimated from the experimental results in the plateau region. Also, some important mechanical parameters, such as Young's modulus ( E), yield strength ( Y), fracture toughness ( K) and brittleness index ( B), were calculated for both additions. The results clarified that these parameters are strongly dependent on both the applied loads and the nano-oxides addition. [ABSTRACT FROM AUTHOR]