Fabrication and characterization of nanocrystalline Nb–W–Mo–Zr alloy powder by ball milling

A superfine nanocrystalline Nb–W–Mo–Zr alloy powder was successfully prepared by high energy ball milling at room temperature. The particle size, morphology, and structural changes were characterized by means of laser particle size analysis (LPSA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Experimental results showed that milling velocity was a decisive factor in controlling the production of alloy powders. A 450 rpm-ball milling had led to nanocrystalline Nb–W–Mo–Zr alloy powder particles with a crystallite size of 14 nm. With 250 rpm velocity, cold welding was found to be the dominant mechanism during milling without formation of any solid solution even after 60 h of milling time.

► A superfine nanocrystalline Nb based alloy powder was prepared at room temperature. ► The morphology changes and structural evolutions were investigated. ► The effects of milling velocity, time and alloying mechanism were discussed.