Tem Observation Of Age-Hardening Precipitation In Mg-Gd-Y Alloys As Different Gd/Y Ratio

Abstract

In this study, the early stage of aging in Mg-Gd-Y alloys has been observed by transmission electron microscopy (TEM), high angle annular dark field – scanning transmission electron microscopy (HAADF-STEM) and calculations of images and electron density and bond overlap population (BOP) by first principal to understand the origin of precipitation in this alloy. The small hexagon of 0.37 nm is the first precipitate in this alloy, and this is the evidence of short range ordering of D019 structure. This is referred as the pre β”-phase. In the peak aged condition, β’ phase with bco structure was mainly observed.

Keywords

• Mg-RE alloy
• precipitation behavior
• TEM
• HAADF-STEM