부산대학교 도서관

A kind of bulk metallic glass composites (BMGCs) with ex situ tungsten (W) particles and in situ dendrites were designed and successfully prepared through infiltrating Ti40.9Zr30.4Nb4.2Cu7Ni1.7Be15.8 (at.%) melt into the W preforms at different temperatures of 1103-1243 K. X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements show the dendrites change from single bcc phase to the mixture crystals along with the significant increase in the volume fraction due to the more W dissolution when the casting temperature increases over 1183 K. With such the microstructural evolution, the mechanical properties change significantly from high strength and ductility along with work hardening capacity to the reduced strength and ductility along with work softening capacity. The samples prepared at 1123 K exhibit the optimal mechanical properties including the yield strength of ~ 1670 MPa, the maximum fracture strength of ~ 2080 MPa and the plastic strain of ~ 26%, which is attribute to the cooperative deformation mechanism between W particles and in situ BMGC matrix. These findings deepen the understanding of the cooperative deformation of composites containing the multiple phases and shed light on design BMGCs for specific application.