About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
|
Symposium
|
Aluminum Alloys: Development and Manufacturing
|
Presentation Title |
Strengthening Mechanisms of Mn Addition in Al-Mischmetal-(Ni)-based Eutectic Alloys |
Author(s) |
Jie Qi, David C. Dunand |
On-Site Speaker (Planned) |
Jie Qi |
Abstract Scope |
Manganese is an effective solid solution strengthener in aluminum alloys due to low diffusivity and is chosen for alloying into Al-Mischmetal(-Ni) (MM—a sustainable mixture of Ce, La, and Nd) eutectic alloys. However, the co-existence of Mn with MM and Ni often leads to the formation of undesirable primary intermetallic (IM) compounds. This research identifies the strong tendency for Al-Nd-Ni-Mn primary IM formation and successfully mitigates it, ensuring Mn remains in the Al matrix to maximize solid-solution strengthening. The designed Al-MM-Mn-Ni alloys exhibit nearly doubled hardness of base Al-MM alloys, with excellent hardness retention and coarsening resistance after exposure to 300, 350, and 400 ēC for up to 8 weeks. The precipitation behavior of Mn solute under thermal exposure is thoroughly investigated. Additionally, Mn alloying significantly improves creep resistance at 300 ēC. The alloy Al-9MM-4Ni-0.8Mn emerges as one of the most creep-resistant aluminum alloys with solid-solution and eutectic strengthening mechanisms. |
Proceedings Inclusion? |
Planned: Light Metals |
Keywords |
Aluminum, High-Temperature Materials, Mechanical Properties |