Laminar TiZr-based bulk metallic glass composites with improved mechanical properties

摘要

A novel strategy to design bulk metallic glass composite is proposed. The foils with the composition of the beta phase in the in-situ TiZr-based composite are prepared. The in-situ composite matrix and the beta foils are composited at the semi-solid temperature using the modified melt infiltration method. The mechanical properties of the newly prepared laminar composite reinforced with both ex- and in-situ beta phases are improved remarkably. The composite shows controllable structure based on the phase equilibrium, and the corresponding mechanism is discussed thermodynamically. The interaction kinetics is studied by the modified liquid-bridge experiments and a dissolution kinetics model is deduced. The laminar composite shows obvious plasticity and work hardening behavior because of the introduction of multiscale ductile beta phase. The multiple shear bands in the metallic glass and the beta phase, and the phase transformation of beta to alpha '' contribute to the high performance of the composite. This study provides a new design approach to manipulate the microstructure and further improve the mechanical properties of the composites.