Deformation behavior of a Ti66Cu8Ni4.8Sn7.2Nb14 nanostructured composite containing ductile dendrites

The deformation behavior of multicomponent Ti66Cu8Ni4.8Sn7.2Nb14 composite containing primary dendrites embedded in a nanoeutectic matrix was studied under uniaxial compression. The evolution of slip and shear bands has been investigated at various stages of deformation. This type of advanced composite not only displays a high compressive plasticity of 31.8%, but also exhibits high fracture strength of ≈2.02 GPa (true fracture strength 1.38 GPa). Pronounced work hardening was observed after yielding. The surface deformation morphology reveals that the work hardening behavior of the composite is related to the plastic deformation of the dendritic phase through slip bands and the interaction of shear bands in the nanostructured matrix with the hardened dendrites. The nucleation of shear band occurs at a certain amount (8%) of plastic deformation at the dendrite–nanoeutectic matrix interface. The final stage of compression proceeds through passing of the shear bands through the work-hardened dendrites into the nanoeutectic matrix, whereby the propagation of the shear bands in the matrix is retarded by the nanoscale phases.