MODELING OF MECHANICAL ALLOYING .1. DEFORMATION, COALESCENCE, AND FRAGMENTATION MECHANISMS

A model of the mechanical alloying process, applicable to a single collision event involving ductile species, is developed. Simple physical models are constructed that allow development of analytical expressions for particle shape and hardness changes during a collision and stipulation of criteria for particle fracture and cold welding. These provide a ''snapshot'' of that which transpires during a single collision event. The model also accounts for the heterogeneity of deformation within the powder trapped between colliding media. This heterogeneity, together with the model criteria, can then be incorporated within a computational scheme capable of predictive description of the evolution of powder morphology and properties during mechanical alloying, as will be described in a subsequent article.