Unusual mechanical behaviour of the intermetallic phase Nb2Co7

Single-phase alloys of the monoclinic intermetallic phase Nb2Co7 were investigated with respect to their mechanical behaviour. The material can be strongly deformed at room temperature by hammering without shattering or fracturing and it can be strained in compression to at least 5% without fracture. At the same time, Nb2Co7 behaves like a brittle material when tested under bending or tensile load. The mechanical properties of this phase were systematically studied by microhardness, compression, tensile and bending tests and the microstructure was analysed by light-optical and scanning electron microscopy before and after testing.