Synthesis of Mg-Cu-Ti based amorphous alloys by mechanical alloying technique

This study examined the behavior of amorphous Mg-Cu-Ti based alloys synthesized by mechanical alloying technique. The microstructural evolution during mechanical alloying of the mixed powders was investigated by both X-ray diffraction and scanning electron microscopy. The phase stabilities of the as-milled powders were analyzed by the differential scanning calorimetry. Differential thermal analysis on the 12-h milled ternary Mg-Cu-Ti powders reveals endothern-k peaks in the Mg40Cu40Ti20 and Mg40Cu35Ti25 at around 550 K and no such a peak is observed in the another ternary compositions. For the ternary and quaternary Mg-Cu-Ti based alloys, several amorphous powders were found to exhibit a wide supercooled liquid region before crystallization. The temperature interval of the supercooled liquid region defined by the difference between Tg and Tx, i.e. Tx-Tg, is 54K for Mg40Cu40Ti20, 53K for Mg40Cu40Ti25, 51K for Mg40Cu40Ti23B2, 62 K for Mg40Cu40Ti21Sn4, and 74 K for Mg40Cu40Ti21Ni5. As the results demonstrated, the small addition of Sn and Ni significantly improved the glass forming ability of the Mg-Cu-Ti based amorphous alloys.