W_f/Zr-based Bulk Metallic Glass Composites And Its High-velocity Impact Behavior

The fabracation, mechanical properties, especially high velocity impact behavior ofW_f/Zr based bulk metallic glass matrix composites were investigated whileZr_41.25Ti_13.75Cu_12.5Ni₁₀Be_22.5 acted as amorphous matrix and tungsten fiber reinforcement.The main results were followed:Step temperature-controlled and rapid quenching method was invented to prepareamorphous alloys and W_f/Zr based bulk metallic glass matrix composites to avoid theshortages of methods at present. Samples of W_f/Zr based bulk metal glass matrixcomposites without defect with the size ofφ17×100mm³ were successfully prepared withoptimized technical parameters.The compressive strength of W_f/Zr based bulk metallic glass matrix compositesincreases with the volume faction of tungsten fiber. The compressive strength increases24.5% from 2000MPa to 2560MPa when the volume faction of W_f increases from 0% to70%. The compressive strength increases 13% comparing with the reported maximumstrength of 2250MPa. At the same time, the strain and fracture mode of composites changewith the volume faction of tungsten fiber: when the volume faction is less than 50%, thestrain increases and fracture mode is shearing and splitting; when the volume faction ismore than 50%, the strain decreases. When the volume faction is 50%, plastic strainreaches maximum with the value of 22.5%, increased 25% comparing with the maximumstrain of 18% in literature.The dynamic compressive strength of composites increases with stress rate below3000s^-1. Being different from the unique vein pattern under quasistatic compress, adiabaticshear fracture occurs at high stress rate in dynamic compressive test. In addition to the veinpatterns in the fractural surface, some melting area is also observed.The simulation results with the constitutive model of elasticity-ideal plastic with straindisabled showed that W_f/Zr based metallic glass composites penetrators has the"self-sharpening" effect during the penetrating. The decrease of kinetic energy of W_f/Zrbased metallic glass composites is much slower than that of 93W penetrators.