Wetting of polycrystalline W by molten Zr55Al10Ni5Cu30 alloy

Wetting of polycrystalline W substrates by a molten Zr55Al10Ni5Cu30 alloy was studied using a modified sessile drop method at 1123–1173 K in high vacuum. Good wettability with final stable contact angles of 4–11° was observed. The Zr adsorption at the solid–liquid interface and further diffusion to the front of the triple line should be the primary reason for the enhanced wettability and the formation of a diffusion band. Moreover, the interfacial microstructure is dictated by temperature. A higher temperature substantially promotes the dissolution of W into the liquid alloy and then precipitation of the W2Zr phase. Accordingly, the processing temperature should be accurately controlled in preparation of the Zr-base bulk metallic glass (BMG) matrix composites reinforced by W particulates or fibers.