Ion-beam Induced Phase Transformations in Fe0.84Mn0.16 Alloy

R. A. BORZI; J. DESIMONI; L. D. JUNCIEL; G. PUNTE; R. C. MERCADER; E. D. CABANILLAS; A. FILEVICH

Cuzco

Congreso; Fifth Latin American Conference on Applications of the Mössbauer Effect, LACAME ?96; 1996

Universidad Nac. Mayor de San Marcos

ION-BEAM INDUCED PHASE TRANSFORMATIONS IN Fe0.84Mn0.16 ALLOY R. A. Borzi, J. Desimoni, L. D. Junciel, G. Punte, R. C. Mercader Departamento de F¨ªsica, Facultad de Ciencias Exactas, UNLP. C.C.N¡ã 67, 1900 La Plata, Argentina. E. D. Cabanillas Departamento de Materiales, Comisi¨®n Nacional de Energ¨ªa At¨®mica, Buenos Aires, Argentina. A. Filevich Laboratorio Tandar, Comisi¨®n Nacional de Energ¨ªa At¨®mica Buenos Aires, Argentina. The influence of the treatment on the transformations between the three different metallurgical phases (¦Á', ¦Å and ¦Ã) found in the iron rich region of Fe-Mn alloys, are currently the subject of many investigations. Under thermal or mechanical processes, different factors influence the process: initial state of tension of the matrix, presence of one or more phases, degree of deformation, or distribution of the manganese atoms. In this work, CEMS and XRD experiments are performed to investigate the modifications induced at the surface of an Fe0.84Mn0.16 alloy by 360 keV C ion bombardment. The increase in the amount of the magnetic ¦Á' (bcc) at the expense of the ¦Å (hcp) phase (both originally present) shows that the defects created by the irradiation are the driving force of the transformation. An additional effect observed was the change in the originally random distribution of Mn atoms in the ¦Á' lattice.