After 29% deformation, in the EBSD map of the alloy austenite and α′ martensite were identified ( Fig. 6). The structure has a banded character. The occurrence of the Kurdjumov–Sachs relationship between the γ and α′ phases was determined ( Fig. 6d and e).
TEM microstructures confirm X-ray phase analyses, and also EBSD data. In the deformed material, numerous stacking faults are observed, and they A 80426 occur individually (Fig. 7a and b), or are aggregated, making bands (bundles) and leading to formation of the ε phase. An increase in deformation causes a change in zygospore mechanism. Austenite is dominated by deformation twins ( Fig. 8a). ε martensite plates are observed after 29% deformation ( Fig. 8b). Increasing the deformation to 56% causes an increase in the quantity of α′ martensite ( Fig. 9) and the ε phase is not observed.
Fig. 7. TEM micrographs of Fe–21Mn–3Si–3Al alloy after 11% cold-rolling.Figure optionsDownload full-size imageDownload as PowerPoint slide