ABSTRACT
The intense mechanical deformation experienced by powder particles during mechanical alloying (MA) results in the generation of a variety of crystal defects (dislocations, grain boundaries, stacking faults, antiphase boundaries, vacancies, and so forth). As mentioned earlier, the balance between cold welding and fracturing among the powder particles is responsible for structural changes and the alloying that occurs in them. However, crystal defects also play a major role in the alloying behavior, due to enhanced diffusivity of solute atoms in the presence of increased defect density. Furthermore, as mentioned in Chapter 5, a number of process variables during milling also affect the final constitution of the milled powder. Among these, the temperature experienced by the powder particles during milling is very important in determining the nature of the final powder product. This is again related to the increased diffusivity of solute atoms for alloying to occur.
