Effect of WC content on glass formation, thermal stability, and phase evolution of a TiNbCuNiAl alloy synthesized by mechanical alloying

摘要

Amorphous Ti_(66)Nb_(13)Cu_8Ni_(6.8)Al_(6.2) alloy powders with different tungsten carbide (WC) contents were synthesized by mechanical alloying. Outstanding differences in particle size, thermal stability, glass-forming ability, and phase evolution are found for the synthesized Ti-based glassy powders with different WC contents. This is attributed to the fact that the WC was partially alloyed into the glassy matrix and the matrix element Ti was also partially alloyed into the WC particles. The obtained glassy powders exhibit a wide supercooled liquid region above 64 K. Meanwhile, the main crystalline phase is the ductile β-Ti with a high volume fraction in the crystallized alloy powders. These two aspects offer the possibility of easily preparing a plasticity-enhanced bulk composite in the supercooled liquid region by powder metallurgy, which couples the nanosized WC particles with in situ precipitated ductile β-Ti phase.