Mechanical properties of Bi(Pb)-Ca-Sr-Cu-O glass-ceramic superconductors

This paper reports on the fracture toughness of Bi(Pb)-Ca-Sr-Cu-O glasses and glass-ceramic superconductors which crystallized from glasses investigated by means of the Vickers indentation microfracture method and the three-point bending technique. The glass-ceramics mainly consisted of the Bi2CaSr2Cu2Oy (80K) superconducting phase with different preferred orientations. Ceramics with different preferred orientations showed different hardness. The polycrystalline Bi(Pb)-Ca-Sr-Cu-O ceramics were more ductile than the glasses. The fracture toughness of the crystalline ceramics was higher than that of glasses. It was found that the toughness values of crystallized glass can be increased with PbO substitution for Bi2O3