Multistage homogenization process of aluminum alloy 2618

Abstract Single‐, two‐, and three‐stage homogenization treatments of heat‐resistant alloy 2618 were conducted in this study. Results reveal a low melting point Al₂CuMg phase and high melting point Al₂Cu phase in the as‐cast aluminum alloy 2618. After single‐stage homogenization at 495 °C for 10 h, the Al₂CuMg phase dissolves completely, but the Al₂Cu phase cannot be completely dissolved even once the homogenization time is prolonged to 18 h. After the alloy 2618 are homogenized using two stages: 495 °C for 10 h and 520 °C for 8 h, a portion of the Al₂Cu phase remains in the alloy. The Al₂Cu phase remains undissolved even after prolonged time. After the two‐stage homogenization treatment at 495 °C for 10 h and 540 °C for 5 h, the high melting point Al₂Cu phase completely dissolves but overburn occurs. After the alloy 2618 are homogenized using three stages at 495 °C for 10 h, 520 °C for 5 h, and 540 °C for 3 h, the Al₂Cu phase completely dissolves and no overburn is detected. The three‐stage homogenization treatment is an effective method for dissolving the high melting point Al₂Cu phase in the alloy 2618 and increasing their overburn temperature and solid solution temperature.