Abstract: Al-Cu-Mn alloys are used in components in automotive and aircraft industry which work at high temperature. Recent research is focused on Al-Cu-Mn alloys to promote the formation of Mnrich (T phase) particles. This phase has high thermal stability and has potential to improve the high temperature strength of these alloys. In this study, the effect of Mn/Cu ratio on microstructure and mechanical properties of two Al-Cu-Mn alloys (Mn/Cu ratio = 0.2, 0.4) is investigated by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and high temperature tensile testing. Results reveal that as-cast microstructure of both the alloys consists of trunks of α-Al dendrites surrounded by Cu-rich interdendritic region. After solution treatment, a great amount of Al-Cu-Mn intermetallic compound particles are found to precipitate adjacent to this region. Alloy with high Mn/Cu ratio exhibits high strength at high temperature due to relatively high amount of Al-Cu Mn (T-phase) particles.
Authors: Soban Muddassir Dar, Hengcheng Liao, and Guangjin Li
Keywords: Al-Cu-Mn Alloy; Microstructure; Mechanical Property; High Temperature Strength