The effect of metal alloying on mechanical properties including hardness and fracture toughness were investigated in three alloys, Ti~0 .33 Al 0.50 (Me)~0 .17 N (Me = Cr, Nb and V), and compared to Ti 0.50 Al 0.50 N, in the as-deposited state and after annealing. All studied alloys display similar as-deposited hardness while the hardness evolution during annealing is found to be connected to phase transformations, related to the alloy's thermal stability. The most