Hardening and softening of FeAl during milling and annealing

Changes in hardness of Fe-40Al powders during milling and during subsequent annealing have been examined and related to the many structural changes occurring. During milling, the material becomes significantly disordered with a small domain size and many vacancies, and refines to a nano-scale grain size, while on subsequent annealing at progressively higher temperatures these structural defects are lost as the material re-orders, loses point defects and as the grains grow to large sizes. The increase in hardness during milling can be explained by the combined contributions of vacancy hardening, ordered domain/particle hardening, and by disorder hardening within the ordered regions. Softening during annealing occurs as the domain/particle hardening, disorder hardening and vacancy hardening are successively lost. Dislocation-induced work hardening and grain size hardening are believed to play only minor roles in affecting the material hardness.Peer Reviewe

Disordering of B2 intermetallics by ball milling, with particular attention to FeAl

Our understanding of the disordering, partial or complete, of B2 intermetallics during intense milling is reviewed choosing, in particular, the FeAl intermetallic as an example, and making especial effort to interpret the changes occurring in terms of the deformation mechanisms operating during milling and the crystalline and structural changes produced. The ease of disordering can be correlated with the relative energies of the possible point defects produced during milling, or by the corresponding types of active dislocation. Attempts at modelling the structural changes produced by such intense deformation appear to be in good agreement with detailed structural analyses that have been carried out. Many aspects of the processes occurring are still poorly understood, however, and there remains scope for further investigation

Disordering of B2 Intermetallics by Ball Milling, with particular attention to FeAl

Trabajo presentado en el Metastable, Mechanically Alloyed and Nanocrystalline Materials (ISMANAM), celebrado en Oxford (Inglaterra), del 9 al 14 de julio de 2000Our understanding of the disordering, partial or complete, of B2 intermetallics during intense milling is reviewed choosing the FeAl intermetallic as an example, and making especial effort to interpret the changes occurring in terms of the deformation mechanisms during milling and the crystalline and structural changes produced. The ease of disordering can be correlated with the relative energies of possible point defects produced during milling, or by the corresponding types of dislocations. Attempts at modelling structural changes produced by intense deformation appear in good agreement with detailed structural analyses. Many aspects of the processes occurring are still poorly understood, however, and there remains scope for further investigation