Accelerated and enhanced aging hardening response of the pre-aged and HPT-processed Mg-Zn-Y alloy by HAADF-STEM

The age hardening response of nanocrystalline Mg-Zn-Y alloy processed by a combination of aging treatment (T6) and high pressure torsion (HPT) was systematically investigated by HAADF-STEM. The results show that T6 + HPT-processed Mg-Zn-Y alloy exhibits distinct age hardening behaviour during aging at 90 degrees C, which is also the lowest temperature for strengthening Mg alloy by age treatment. The hardness increases sharply during the early period of aging at 200 degrees C, and the peak hardness reaches a maximum of similar to 135 HV after 2 h, indicating that HPT can significantly accelerate and enhance the second artificial aging response. (C) 2019 Elsevier B.V. All rights reserved.