Microstructural, Mechanical, Thermal, and Magnetic Properties of the Mechanically Alloyed and Consolidated Al–16 wt. % Mn–7 wt. % Cu Alloy
Year: 2025
Type: article
Abstract: The effect of severe plastic deformation during milling and conventional and Spark Plasma Sintering (SPS) on the wt. % microstructural, structural, thermal, magnetic, and mechanical properties of the Al–16 wt. % Mn–7 wt. % Cu alloy was studied. A milling process for up to 24 h (A24) leads to microstructure refinement and the presence of Al, Mn, and Cu solid solutions. The energy dispersive spectroscopy (EDS) analysis reveals the existence of Cu–Al, Mn–Al, and Al–Mn enriched particles. The powders exhibit weak ferromagnetism and an exchange bias (EB) behaviour that decreases with increasing milling time. The Ms values fitted using the law of approach to saturation (LAS) are comparable to the experimental values. The exothermic and endothermic peaks that appear in the differential scanning calorimetry (DSC) scans in the 500–900 °C range on heating/cooling are related to different phase transformations. The crystal structure of the A24 powders heated up to 900 °C (A24_900 °C) consists of a dual-phase microstructure of Al20Cu2Mn3 nanoprecipitates (~28%) and Al matrix (~72%). The sintering of the A24 powders at 500 °C for one hour (A24S) leads to the precipitation of Al6Mn, Al2Cu, and the Al20Cu2Mn3 T-phase into the Al-enriched matrix. In contrast, the consolidation by SPS (A24SPS) leads to a mixture of an Al solid solution, Al6Mn, T-phase, and α-Mn with an increased weight fraction of the T-phase and Al6Mn. The sintered samples exhibit the coexistence of a significant PM/AFM contribution to the M-H curves, with increasing Hc and decreasing EB. A higher microhardness value of about 581 HV is achieved for the A24SPS sample compared to those of the A24 (68 HV) and A24S (80 HV) samples.
Source: Magnetochemistry
Institutions: Badji Mokhtar-Annaba University, Universitat de Girona
Language: English
Subfield: Metals and Alloys
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,654
OpenAlex ID: W4412201489