Study of the effect of Mn and Cu in Fe–Mn–Al–C–Cu alloys by ICEMS and XRD

Experimental analysis of magnetic and structural properties of Fe–Mn–Al–C–Cu alloys with compositions FexMn0.915 − xAl0.075C0.01 (series A) and FexMn0.912 − xAl0.075C0.01Cu0.003 (series B), 0.500 ≤ x ≤ 0.800, in steps of 0.050 is presented and discussed. The analysis was performed by integral conversion electrons Mössbauer spectrometry and X-ray diffraction at room temperature. The results suggest, for both series of alloys, that for the highest Mn content, samples exhibit an antiferromagnetic behavior, typical of the FCC or austenite FeMn phase rich in Mn; for those of low Mn content, the coexistence of paramagnetic austenite, typical of the FeMn alloy poor in Mn, a ferromagnetic BCC or ferrite phases can be observed, while for the lowest Mn content, only ferromagnetic (FM) phase tends to prevail. The FM phase is associated to the BCC FeMnAl as was corroborated by X-ray diffraction. The samples with the highest Mn content, the influence of Cu addition is to reduce the mean hyperfine field and to stabilize the antiferromagnetic behavior.