PHASE-TRANSFORMATION OF THE COMPOUND V3GA INDUCED BY MECHANICAL GRINDING

The A15 intermetallic compound V3Ga was subjected to grinding in a high-energy ball mill. X-ray diffraction showed that the material transformed from the A15 phase to the high-temperature BCC solid solution after 40 hours of grinding. This state did not change upon further milling. Differential scanning calorimetry revealed two exothermic peaks with a total heat content of 3.0 kJ mol-1. After the heating the material again exhibited the A15 structure. The activation energy of the first peak turned out to be the same as the activation energy for reordering of thermally disordered V3Ga. The results were interpreted in terms of atomic disordering.