A HRTEM-EDS-SAED Study of Precipitates in Mg-Zn-Zr Alloy
Abstract
In this study, aging heat treatment was performed on extruded Mg-Zn-Zr alloy. Aging was performed on as-extruded samples at 180°C for 1-2-4-8 and 24 hours. Microhardness tests were made to obtain the aging curve. Detailed transmission electron microscopy (TEM) examinations such as selected area electron diffraction (SAED), energy dispersive spectrometry (EDS), and high resolution transmission electron microscopy (HRTEM) were used to investigate the microstructure, second phases, and precipitates. Size, type, and morphologies of second phases and precipitates were studied aided by advanced transmission electron microscopy techniques. With the help of hardness test results peak aged condition was found to be 8 hour aging. TEM examinations were detailed for the 8-hour aged sample. It was observed that the precipitates responsible for age hardening were MgZn2. Moreover, the majority of these precipitates were β’1 phase.
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