Thesis - Oztek_Muzaffer_T_200508_MA

grain boundaries increases the total hydrogen affinity of the material. Another effect of
milling is the removal of the oxidized surface layers that create a barrier for hydrogen
absorption. During milling in an inert atmosphere, active fresh metal surfaces are created,
which will readily dissociate H 2 upon exposure. Thus, after activation by mechanical
milling, a material can readily react with hydrogen [46]. One important feature of ball
milling is that it allows the production of alloys from elements with high vapor pressure
or poor miscibility [48].
Figure 2. Energy diagram for metastable phase formation by mechanical alloying.
The phase and/or microstructure of a material after milling depend on several
variables. These are listed below along with their influences on the final product.
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