EXPERIMENTAL FACTORS INFLUENCING ECAP:

When materials are processed using ECAP, several different factors influence the workability and the micro structural characteristics of the as-pressed billets. These factors fall into three different categories. First, there are factors associated directly with the experimental ECAP facility, such as the values of the angles within the die between the two parts of the channel and at the outer arc of curvature where the channels intersect. Second, there are experimental factors related to the processing regimes where some control may be exercised by the experimentalist including, for example, the speed of pressing, the temperature of the pressing operation and the presence or absence of any back pressure. Third, there are also other factors which may play a role influencing the extent of grain refinement. These include the processing routes and the total number of passes imposed on the sample.