dAmorphization and crystallization behaviors of Ti70Ni15Al15 and Ti41.5Zr41.5Ni17 powders during mechanical alloying (MA) and subsequent heat treatments are studied. Fully amorphous powders are prepared by MA of the elemental powder mixture of the nominal composition of Ti70Ni15Al15 During continuous heating of the amorphous powders in DSC, two exothermic events are observed. The first exothermic event corresponds to the formation of a supersaturated alpha -Ti phase of hexagonal close-packed structure. The growth kinetic of the alpha -Ti phase is sluggish forming nanostructured alpha -Ti matrix. The second exothermic event is associated with the solid-state transformation of the meta-stable alpha -Ti into the equilibrium phases, Ti2Ni and Ti3Al. Amorphous powders are prepared after MA for more than 30 hours in the mixture of elemental powders with the nominal composition of Ti41.5Zr41.5Ni17 The amorphous powder transforms into the quasicrystalline phase in the temperature range of 300-400 degreesC during continuous heating in DSC. Based on the observed amorphization and crystallization behavior Ti70Ni15Al15 and Ti41.5Zr41.5Ni17 powders, bulk materials consisting of amorphous phase with small fraction of nanocrystals in the Ti-Ni-Al system and quasicrystalline phase in the Ti-Zr-Ni system can be fabricated in a hot press using MA powders.