Wettability and reactivity between B_4C and molten Zr_(55)Cu_(30)Al_(10)Ni_5 metallic glass alloy

摘要

The isothermal wetting and spreading behaviors of molten Zr_(55)Cu_(30)Al_(10)Ni_5 metallic glass alloy on B_4C substrates were studied using a modified sessile drop method at 1133-1253 K in a high vacuum. A distinct reaction layer consisting of ZrB_2 and ZrC_x was produced at the interface and displayed good wettability with the molten alloy. The entire spreading kinetics could be characterized by four representative stages: (ⅰ) an initial rapid spreading presumably driven by adsorption of the active Zr atoms at the solid-liquid interface, (ⅱ) a quasi-linear and (ⅲ) a linear spreading stage controlled by the chemical reaction between Zr and B_4C in both cases, and (iv) an approach-to-equilibrium stage with precipitation of crystals in the liquid. An increase in temperature promotes the wetting and reaction. In view of the reasonable wettability and reactivity, there is a potential for preparing Zr-base bulk metallic glass matrix composites reinforced by in situ ZrC-ZrB_2 hybrid ceramic participates using B_4C as a reaction agent by way of an infiltration synthesis technique.