Dynamic mechanical behavior of a Zr-based bulk metallic glass composite

Dynamic mechanical analysis (DMA) was used to study the viscoelastic properties of a Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 (LM2) bulk metallic glass (BMG) matrix composite. The temperature spectrum and the frequency spectrum were tested by three point bending. We revealed that the relaxation process of the LM2 composite is different from the single amorphous alloys. The unique superimposition of glass transition (a-relaxation) and beta-phase transformation during DMA results in double peaks on the loss modulus evolution and a plateau on the storage modulus evolution. The numerical analysis of the isothermal spectrum suggests that the dynamic relaxation behavior of the LM2 composite cannot be described by a single classical relaxation model. A coupling model is instead proposed to well quantify the coupling effect of the a-relaxation and beta-phase transformation in the LM2 BMG composite. Our findings provide an insight into understanding the more complex structural relaxation of BMG composite than monolithic BMGs. (C) 2015 Elsevier Ltd. All rights reserved.