Twins and polytypic stacking faults in the ν phase formed in rapidly quenched Mn-Si alloys

• Published in: Materials letters 2020-07, Vol.271, p.127746, Article 127746
• Main Authors: Gao, C.T., Cheng, S.D., Mi, S.B., Qiang, J.B., Wang, Y.M.
• Format: Article
• Language: English
• Subjects: Atomic structure; Binary alloys; Crystallography; Defects; Electric arc melting; Electron microscopy; Interfaces; Intermetallic alloys and compounds; Materials science; Microstructure; Rapid quenching (metallurgy); Scanning transmission electron microscopy; Silicon base alloys; Stacking faults; Structural models; Twin boundaries
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.127746

•Twins and polytypic stacking faults form in the rapidly quenched ν phase.•Subunits of the ν phase reconstruct at twin boundaries and stacking faults.•An orthorombic structure forms across twin boundaries in the ν phase.•Monoclinic structures form across polytypic stacking faults in the ν phase. Mn-rich Mn-Si binary alloys containing the ν phase have been prepared by arc-melting and rapid-quenching methods. In comparison, twins and polytypic stacking faults (SFs) are observed in the rapidly quenched ν phase, and the atomic-scale structure properties of twins and SFs have been determined by using aberration-corrected scanning transmission electron microscopy techniques. Both twins and SFs break the crystallographic symmetry of the ν phase, and lead to reconstruction of the subunits of the ν phase at twin boundaries and SFs. On the basis of experimental results, new structural models are proposed to explain the twin and SFs formation in the rapidly quenched ν phase.