Part of the book: Recrystallization
In this chapter, two techniques have been proposed for grain refinement in Cu‐Cr and Cu‐Fe alloys in different heat treatment conditions. First method, known as rolling with cyclic movement of rolls (RCMR), is appropriate for the manufacturing of ultrafine grained sheets and plates. The second method is called compression with oscillatory torsion (COT). Structural investigations of alloys were carried out, in particular, using a cold field emission gun/scanning electron microscope (FEG/SEM) equipped with an electron backscattering diffraction (EBSD) detector and a scanning transmission electron microscope (STEM). Quantitative studies of the microstructure based on the STEM images were performed using the “MET‐ILO” software package. Mechanical properties were determined using an MST QTest/10 instrument equipped with digital image correlation (DIC). Based on the SEM and STEM observations, it has been shown that the alloys may exhibit a refinement of the ultra fine grained (UFG) structure in the 200–500 nm range with a mixture of low‐ and high‐angle boundaries. Although the microstructure was refined significantly, the heterogeneity of the microstructure after the application of a high total effective strain is observed. Moreover, the low‐angle boundaries formed at the early stages do not continuously transform into high‐angle boundaries.
Part of the book: Severe Plastic Deformation Techniques