Effect of APB Microsegregation on the Strength of Ni 3 Al with Ternary Additions

Solid solution strengthening for stoichiometric and non-stoichiometric alloys is studied using a microscopic model that takes into account the micro-segregation of the alloying additions and of the host atoms to antiphase boundaries. Experimental results for four ternary intermetallic compounds, Ni-Al-Si, Ni-Al-Ti, Ni-Al-Hf and Ni-Al-V, are analyzed in the light of the theoretical model. It is found that the athermal increment of yield strength for both stoichiometric and non-stoichiometric alloys can be explained using solid solution strengthening theory provided that the local concentration at the {111} antiphase boundaries between superpartial dislocations is used.