Synthesis and stability of L1<SUB>2</SUB>-Al<SUB>3</SUB>Ti by mechanical alloying

The present paper reports the synthesis of nanocrystalline L1<SUB>2</SUB>-Al<SUB>3</SUB>Ti by mechanical alloying (MA) of elemental blends of composition Al<SUB>67</SUB>M<SUB>8</SUB>Ti<SUB>25</SUB> (M=Cr, Mn, Fe, Co, Ni and Cu). Among all the ternary elements studied, Cu appears to be the best in stabilizing the nanocrystalline L1<SUB>2</SUB>-Al<SUB>3</SUB>Ti phase in the as milled condition. However, the results of annealing in the temperature range of 823-1273 K indicate that the L1<SUB>2</SUB>-Al<SUB>3</SUB>Ti phase is stable up to higher temperature in case of Cr containing alloy in comparison to that containing Cu. The as milled L1<SUB>2</SUB>-Al<SUB>3</SUB>Ti phase does not show the superlattice peaks on even annealing up to 1273 K, which has been attributed to the nanocrystalline nature of the phase and the low relative intensity of superlattice peaks of L1<SUB>2</SUB>-Al<SUB>3</SUB>Ti phase even in the fully ordered structure