Multifilamentary MgB2 wires fracture behavior during the drawing process

► The fracture behavior of 6+1 filamentary MgB2 superconductive wires has been analyzed. ► The microstructure of the wire has a great influence on its fracture behavior. ► The fracture is also influenced by drawing conditions and materials properties. The fracture behavior of 6+1 filamentary MgB2 superconductive wires is presented here. The composite wires were fabricated by in situ Powder-in-Tube method using Nb as a barrier and copper as a stabilizer. The microstructure of the material has a great influence on its fracture behavior. The microstructural aspects of crack nucleation and propagation are discussed. It shows that there are complicated correlations between fracture behavior and the main influencing parameters, which contain specific drawing conditions (drawing velocity, reduction in area per pass), materials properties (strength, yield stress, microstructure) as well as the extent of bonding between the metal sheaths at their interface.