Amorphous Al-50at.% TM (TM; Ti, Zr and Ta) alloy powders have been synthesized by mechanical alloying (MA) and mechanical disordering (MD) using the rod-milling technique. The results show that the MA process for producing amorphous alloys is classified into three stages, while the crystal-to-amorphous transformation via the MD process occurs through one stage. At the intermediate stage of the MA time, the crystalline rod-milled Al-50at.% TM alloys have been transformed completely into amorphous phase at about 700 K by thermally assisted solid state amorphization reaction (TASSA). Contrary to this, the amorphous formation at the final stage of the MA occurs only due to the mechanically driven solid state amorphization (MDSSA).