Abstract
In this study, Mg-8Sn-2Zn-2Al (TZA822) alloys with varying Mg2Sn contents prior to extrusion were obtained by different pre-treatments (without and with T4), and the strengthening response related to micro and nano-size Mg2Sn precipitates in the extruded TZA822 alloys was reported. The results showed that the morphology of nano-size Mg2Sn precipitates exhibits a significant change in basal plane from rod-like to spherical, owing to the decrement in the fraction of micro-size particles before extrusion. Meanwhile, the spherical Mg2Sn precipitates provided a much stronger strengthening effect than did the rod-like ones, which was ascribed to uniform dispersion and refinement of spherical precipitates to effectively hinder basal dislocation slip. As a consequence, the extruded TZA822 alloy with T4 showed a higher tensile yield strength (TYS) of 245 MPa, ultimate tensile strength (UTS) of 320 MPa and elongation (EL) of 26.5%, as well as a lower degree of yield asymmetry than their counterpart without T4. Detailed reasons for the strengthening effect were given and analyzed.
Highlights
Due to the variety of inherent merits such as creep resistance, superplastic behavior at elevated temperatures and good extrudability, Mg-Sn based alloys have attracted great interests, in the extruding industry [1,2]
The microstructures of the specimens were examined by a Leica 2700 M optical microscope (OM, Lecia Microsystem GmbH, Wetzlar, Germany), a Mira 3XMU scanning electron microscope (SEM, TESCAN Ltd., Brno-Kohoutovice, Czech Republic) equipped with an energy dispersive spectrometer (EDS), and a JEM-2100F transmission electron microscope (TEM, JEOL Ltd., Tokyo, Japan)
Varying Mg Sn contents containing TZA822 alloys prior to extrusion were subjected to different pre-treatments 2(without and with T4), and the strengthening response due to micro and nano-size pre-treatments, and the strengthening response due to micro and nano-size
Summary
Due to the variety of inherent merits such as creep resistance, superplastic behavior at elevated temperatures and good extrudability, Mg-Sn based alloys have attracted great interests, in the extruding industry [1,2] This is mainly attributed to the high solidus temperature of Mg2 Sn intermetallic, which could prevent the occurrence of hot shortness when comparing with Mg-Zn and Mg-Al based alloys [3]. Micro-alloying is usually regarded as an effective method for strengthening Mg alloys. Various alloying elements, such as Zn [4,5], Na and. Li [6], Ca [7] and Ag [8] are added to Mg-Sn alloys to improve their strength by grain refinement. Many studies have reported that extruded Mg-Sn-Zn-Al (TZA) alloys exhibit a greater strength than that of commercial
Sign-in/Register to view highlights & summary 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.
