AMORPHIZATION OF THE TIV SYSTEM BY MECHANICAL ALLOYING AND MECHANICAL GRINDING IN A HYDROGEN AND NITROGEN ATMOSPHERE

A TiV system, which does not amorphize in an inert gas atmosphere, has been mechanically alloyed (MA) and mechanically ground (MG) using a planetary ball mill in a hydrogen and nitrogen atmosphere. The products were characterized by x-ray diffractometry, transmission electron microscopy, differential scanning calorimetry, and chemical analysis as a function of milling time and the gas pressure. Amorphization occurs by MA and MG in a hydrogen atmosphere and by MG in a nitrogen atmosphere. Amorphization by MA proceeds by the reaction between TiH2 and pure V in a hydrogen atmosphere, while it proceeds by MG by hydrogen and nitrogen absorption into the metastable beta-TiV alloy and subsequent milling. The difference in the phase formation by MA and MG of the TiV system is discussed based on the gas absorption rate and the solubility of gases.