Grain growth in the two-phase Al-Cu alloys

Abstract

Grain and phase growth in the two-phase Al-Cu alloys containing 6, 11, 1 7, 24 and 33 wt % Cu were investigated by annealing at 535 °C for 0.5–100 h. The grain and phase sizes of the κ phase are seen to be larger than that of the θ phase. The size ofκ phase decreases whereas the size of θ phase increases with increasing copper content in the alloy. As such, the κ phase- and grain-size distributions are broader than the θ phase- and grain-size distributions, but the size range depends on annealing time and alloy composition. The grain sizes of the κ,d _κ, and θ,d _θ, phases can be related to the volume fraction of the θ phase,f _θ, according to the equationd _κ = 0.497d _θ/f _θ.