Microscopic model for mechanical alloying

We present a microscopic model for the mechanical alloying (MA) of a mixture of two or more elemental ductile powders. The MA produces fresh metal/metal surfaces and a high density of dislocations. The model is based on dislocation kinetics and the diffusion of solutes along the dislocation cores. For short time intervals T1, on the order of microseconds, powder particles are subjected to high stresses which exceed their mechanical strength. However, for times T2 on the order of seconds, the powder particles are unaffected by the milling process. During T2, solutes diffuse along the cores of these dislocations. During successive T1 periods, the dislocations are mechanically forced to glide, leaving behind strings of solutes in states of supersaturation. The model is used to explain the formation of extended solid solutions and amorphous alloys, as well as many other unusual effects observed during MA.