Abstract
The outline of the history of mechanical alloying (MA) was presented. The researches on MA of metallic materials in 80's focused mainly on the formation of amorphous alloys. In 90's nanocrystallization by ball milling seemed the major interest. The amorphization by ball milling can be achieved either by mechanical alloying of the mixture of pure elements or by grinding of intermetallic compounds. The heavy rolling of TiNi plate revealed the formation of amorphous phase as shear bands. This suggests that deformation is purely responsible to the amorphization by ball milling. Nanocrystallization by ball milling examined by structural observation revealed a sudden change from work-hardened to nanocrystalline structure. This suggests that when deformation exceeds a certain critical condition, dislocation cell structure changes to grain boundary structure by the rearrengement of dislocations. Some of the previous and future applications of MA were discussed. ODS alloys, ultrafine particles, laminate rolling to produce TiNi thin plate and materials processing by means of mechanochemistry were intoduced.
