Coarsening of γ (Ni-Al solid solution) precipitates in a γ′ (Ni3Al) matrix; a striking contrast in behavior from normal γ/γ′ alloys

Coarsening of γ precipitates in a γ′ (Ni3Al) matrix depends strongly on volume fraction, in dramatic contrast with coarsening of γ′ precipitates. Coalescence of γ precipitates is easy, unlike the resistance to coalescence of γ′ precipitates. We regard this as indirect proof that anti-phase relationships among γ′ precipitates inhibit coalescence.