Effect of solution treatment on microstructure and hardness of rheo-forming AZ91-Y alloy

The microstructure and hardness of rheo-forming AZ91-Y alloy before and after solution treatment (ST) have been investigated by means of optical microscope (OM), scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Vickers. The experiment...

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Bibliographic Details
Main Authors: Zhi-wei Wang, Hong Yan, Wen-xian Huang
Format: Article
Language:English
Published: Foundry Journal Agency 2016-11-01
Series:China Foundry
Subjects:
Online Access:http://ff.foundryworld.com/uploadfile/2016121239138177.pdf
Description
Summary:The microstructure and hardness of rheo-forming AZ91-Y alloy before and after solution treatment (ST) have been investigated by means of optical microscope (OM), scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Vickers. The experimental results showed that the β-Mg17Al12 phase of alloy was nearly dissolved after ST for 5 min. With the increasing of ST duration to 28 h, both the primary and secondarily solidified α-Mg grains faded away. At the same time, the alloy exhibited a much smoother surface due to the diffusion of solute atoms (Al). During ST, the thermal stable phase of Al2Y produced by ultrasonic vibration retained its size and morphology. As the ST duration was increased, the alloy hardness decreased sharply at first, and then gradually reached a minimum level. The alloy’s appropriate ST duration at 410 °C was approximately 28 h.
ISSN:1672-6421
1672-6421