The synthesis and properties of Zr-based metallic classes and glass-matrixcomposites

In this article, the formation of metallic glass composites in the system Z r/Ti-Al-Cu-Ni by partial devitrification or by blending with second-phase p articles through solid-state processing is discussed with respect to the ef fect of second phases on the thermal stability of the glassy matrix and on mechanical properties. The composites exhibit no significant reduction of t he supercooled liquid region as compared to the particle-free metallic glas s. The viscosity of the supercooled liquid increases with an increasing vol ume fraction of particles. The mechanical behavior was characterized by mic rohardness measurements and constant compression rate tests. At room temper ature, there is a significant increase in yield strength with an increasing volume fraction of crystalline phases. At temperatures around the glass tr ansition, the influence of these nanoscaled particles is of minor importanc e. Rather, the homogeneous flow of the composites is determined by Newtonia n viscous flow of the amorphous matrix. This opens a promising route for ea sy shaping of complex parts of bulk metallic glasses at temperatures that a ve above T-g.