The Influence of Cu-Additions on the Microstructure, Mechanical and Magnetic Properties of MnAl-C Alloys.

ABSTRACT: Alloys of the form (Mn54Al44C2)100-xCux (with x?=?0, 1, 2, 4 and 6) were produced by induction melting. After homogenisation and quenching, most of the alloys consist entirely of the retained ?-phase, except for x?=?6, in which the ?-phase was additionally present. After subsequent annealing, the alloys with x???2 consist entirely of a Cu-doped, ferromagnetic ?-phase, whereas the alloys with x?>?2 additionally contain the ?-phase. The polarisation of the alloys at an applied field of 14?T decreases with increasing Cu-content, which is attributed i) to the dilution of the magnetic moment of the ?-phase unit cell by the Cu atoms, which do not carry a magnetic moment, and ii) at higher Cu-contents, to the formation of the ?-phase, which has a much lower polarisation than the ?-phase and therefore dilutes the net polarisation of the alloys. The Curie temperature was not affected by the Cu-additions. The stress needed to die-upset the alloys with x???2 was similar to that of the undoped alloy, whereas it was much lower for x?=?4 and 6, due to the presence of intergranular layers of the ?-phase. The extrinsic magnetic properties of alloys with x???2 were improved by die-upsetting, whereas decomposition of the ?-phase during processing had a deleterious effect on the magnetic properties for higher Cu-additions.

SUBMITTER: Jurries F 

PROVIDER: S-EPMC7217857 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature