Precipitation at superlattice domain boundaries with particular reference to a Copper-aluminium-nickel alloy

The factors favouring precipitation at antiphase boundaries are discussed. In a non-stoichiometric Cu-Al-Ni alloy having the DO 3 structure, it is shown that the precipitation of the γ 2 phase occurs on both B2 and DO 3 type antiphase boundaries but is more pronounced on B2 boundaries. It is deduced that the diffusional segregation of aluminium to the boundaries and the energy of the boundaries are important factors influencing the precipitation reaction.