Mössbauer Study on Atomic Reordering of Cold-Worked Iron-Aluminum Alloys

Kensuke Oki, Shin-ichi Towata, Masaharu Tamiya, Tetsuo Eguchi
1981 Transactions of the Japan Institute of Metals  
The process of atomic reordering of cold-worked Fe-Al alloys in the composition range from about 25 to 35 at%Al has been investigated by means of Mossbauer spectroscopy. Mossbauer spectra for the specimens filed and subsequently annealed were taken at each stage of annealing and analyzed to obtain the distribution of internal magnetic field in the alloys. Furthermore, for the alloy with 24.9 at%Al information on the neighbor configurations of constituent atoms was successfully able to be
more » ... d directly from the Mossbauer spectra by assuming the Gaussian distribution function of internal magnetic field acting on iron atoms with various numbers of iron neighbors, and a detailed process of reordering during annealing was clarified. The ordered alloy with the DO3 type, which is either weakly magnetic or nonmagnetic depending on the composition, became strongly magnetic by cold working. The alloy as-filed was much complicated in structure, and the atomic configuration seemed to be distinctly different from that of the thermally disordered state. The alloy reordered very slowly in the course of annealing by way of the perfect disorder and the B2 type of order. The ordered alloy with the B2 symmetry, which is nonmagnetic, was partially disordered by cold working and changed into a weakly magnetic state. The alloy reordered promptly to its initial state by a relatively low temperature annealing.
doi:10.2320/matertrans1960.22.771 fatcat:xnmmejwy2fbnplmdx3hsvpzyui