MECHANICAL MILLING ALLOYING OF INTERMETALLICS

Recent research on the structure and properties of intermetallic compo unds processed by ball milling-i.e. mechanical attrition-is reviewed. Mechanical attrition includes synthesis of intermetallics from the ele mental powders of their constituents (mechanical alloying) and from mi lling the compound powder (mechanical milling) to provide changes in s tructure and/or microstructure. Mechanical attrition has been used to synthesize intermetallic compound compositions for a variety of reason s: for example (1) materials difficult, to produce by conventional sol idification because of phase equilibria constraints; (2) introduction of unique microstructures to enhance certain properties, and (3) forma tion of metastable structures at intermetallic compositions. The prope rties of intermetallics modified by the structures/microstructures ind uced by mechanical attrition include mechanical behavior, hard magneti c behavior, hydrogen storage, ind catalysis. In addition the extensive plastic deformation observed by TEM in milled nominally brittle inter metallics may offer a means of studying deformation behavior in very b rittle intermetallics at essentially ambient temperature. Copyright (C ) 1996 Elsevier Science Ltd