Abstract
• A novel interfacial precipitate in {10–12} twin boundaries (TBs) is revealed. • Twinning clearly accelerates aging hardening and improves alloy's strength. • Interfacial precipitate mainly formed at BP facets and tilting TBs. Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys. In this work, interfacial precipitation in {10 1 ¯ 2} twin boundaries (TBs) of a cold-stamped Mg−12Gd−1.2Zn−0.4Zr alloy was investigated using atomic-resolution high-angle annular dark-field scanning transmission electron microscopy. Extended periodic segregation of Gd + Zn atoms in the ~86.2° {10 1 ¯ 2} TBs with basal-prismatic facets and in the symmetric tilting TBs (obviously > 86.2°) frequently occurred, resulted in the formation of new interfacial phases, namely β TB ’ having a monoclinic structure in the TBs with two segregation layers and β TB having a tetragonal structure in the TBs with three or more segregation layers. The formation of β TB clearly accelerates peak-aging and improves the alloy's strength.
Sign-in/Register to access full text options 
Free) 
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
