The effect of matrix fracture toughness on the plastic deformation of the metallic glassy composite

• The effect of the glassy matrix fracture toughness on the plasticity of composites was studied.
• The larger plastic strain was obtained in the glassy matrix with higher toughness.
• The formation of shear bands and micro-crack reduced the energy of crack for development.

In the present study, two kinds of bulk metallic glasses (Zr55Cu30Al10Ni5 and Cu46Zr42Al7Y5) with high strength and no plastic strain were adopted as matrixes. Both of them were reinforced by ductile crystalline TiNb with the same volume fraction and particle size. The compression results showed that the plastic strain of TiNb/Zr55Cu30Al10Ni5 composite was higher 292% than that of TiNb/Cu46Zr42Al7Y5 composite. It should be related to the fracture toughness of the glassy matrix. For the glassy matrix with high toughness, the formation of shear bands and micro-crack at the front of the crack reduced the energy of main crack development. It resulted in a large plastic strain. On the other hand, for the brittle metallic glassy matrix, crack developed quickly through the cross section so that no more shear bands was formed. It resulted in the failure of the sample with smaller plastic strain.