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

Abstract

A novel strategy to design bulk metallic glass composite is proposed. The foils with the composition of the β phase in the in-situ TiZr-based composite are prepared. The in-situ composite matrix and the β 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 β 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 β phase. The multiple shear bands in the metallic glass and the β phase, and the phase transformation of β to α" 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.