The effect of Ni₃(Cr_0.2W_0.4Ti_0.4) particles with DO₂₂ structure on the deformation mode and mechanical properties of the aged Ni-Cr-W-Ti alloy

It has been found that the DO₂₂ Ni₃(Cr_0.2W_0.4Ti_0.4) particles play a dominant role in improving the strength of the aged Ni-Cr-W-Ti superalloy. The precipitation of DO₂₂ phase also changed the preferred deformation mode from slip in the as-solutionized alloy into twinning in the aged alloy. Strengthening of the aged superalloy has been determined to be based on shearing mechanism to achieve high cutting stress which is required for partial dislocations to cut through coherent DO₂₂ precipitates and thus produce plastic deformation, resulting in a dramatic increase in yield strength of the aged superalloy.