Abstract

Sequential double extension twinning in AZ31 Mg alloy happens easily during sequential biaxial compressions. Widespread twin-twin interaction leads to the formation of intragranular cross-level twin pairs, each of which can be defined by a primary twin variant PVi (i = 1–6) and its nearby secondary twin variant PVj-SVk (j, k = 1–6, j ≠ i, k) across the twin-twin boundary between them. Theoretically, 9 possible misorientations exist between the two variants. Misorientation between two crystals can be expressed by a pair of rotation axis (r) and the minimum rotation angle (θ). The crystallography of a cross-level twin pair can be described unanimously by the misorientations between PVi and PVj-SVk (i.e., r1-θ1), PVi and PVj (i.e., r2-θ2), and the host grain and PVj-SVk (i.e., r3-θ3), resulting in 13 possible orientation relationships (ORs) that can be expressed explicitly by the three misorientation angles (θ1, θ2, θ3). A cross-level twin pair is a key element of a crossing or crossed twin structure, which is common in the deformed microstructure. Statistical electron backscatter diffraction analysis reveals that OR2 of (49.7°, 60°, 60°) appears the most frequently. Twinning shear transmission is almost irrelevant to the formation of a cross-level twin pair. Although the majority of the identified twins are high Schmid factor (SF) ones with SF > 0.3 and SF ratio > 0.8, SF analysis fails to explain the highly preference of OR2 and the abnormal absence of OR8 of (44.0°, 60°, 60.4°), probably due to the complexity of the formation of a cross-level twin pair.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.