Mechanical Alloying Effect on Cu-(Ta, Mo) Powder

Abstract

Mechanical alloying(MA) of ternary Cu₃₀Ta_70-xMo_x powders was carried out under Ar gas atmosphere. The Cu-Ta and Cu-Mo pairs in the ternary Cu-Ta-Mo system are characterized by a positive heat of mixing, while the heat of mixing of the Ta-Mo pair is negative. The X-ray diffraction, DSC and TEM measurements were used for the study of as-milled and annealed powders. The b. c. c. extended solid solution could be produced by MA of Cu₃₀Ta₃₅Mo₃₅ powders. After heat treatment at 600°C, the Ta-Mo solid solution formed with exclution of the whole copper, the fact of which may be attributable to the affinity of Cu-Ta and Cu-Mo pairs. The amorphization of the Cu₃₀Ta₆₀Mo₁₀ powders was observed after 200 hours of milling, when the content of the tantalum increased. The DSC measurement suggests that the amorphization proceeds through the same process observed in MA of the Cu₃₀Ta₇₀ powders.