Abstract
Abstract The formation process of 6H-phase in rapidly solidified powder metallurgy (RS P/M) Mg 97 Zn 1 Y 2 alloy has been investigated by transmission electron microscopy (TEM) observations. The initial microstructure of RS powder consists of equiaxed grains about 1 μm in average diameter which is surrounded by Y and Zn rich amorphous grain boundaries. The 6H-phase was observed at grain boundaries in the RS ribbon prepared at circumferential speed of 42 m/s. By lowering the circumferential speed, the 6H-phase at grain boundary in the RS ribbon changes to amorphous phase. The amount of Y and Zn segregation at the grain boundary in RS Mg 97 Zn 1 Y 2 alloy increases with decreasing the cooling rate. In other words, the amorphization of grain boundary phase in RS alloy was promoted by the enrichment of Y and Zn. The growth of 6H-phase starts from grain boundary in the RS ribbon annealed at 573 K for 1.2 ks. It can be concluded that the 6H-phase in RS P/M Mg 97 Zn 1 Y 2 alloy crystallizes in the Y and Zn rich amorphous phase at grain boundary and then grows into grain interior during extrusion. In order to clarify the stability of 6H-phase with heat treatment, microstructure changes in RS ribbon are also described.
Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
