Microstructural Characteristics and Mechanical Properties of a Novel Extruded Dilute Mg–Sn–Mn–Ca Alloy

Ming-Ya Zhang,Hong-Xia Wang,Jinghui Li,Wei-Li Cheng,Chen Guo,Mei-Juan Hao,Li-Fei Wang,Xiao-Feng Niu

doi:10.3389/fmats.2019.00321

Ming-Ya Zhang, Hong-Xia Wang + Show 6 more

Open Access

https://doi.org/10.3389/fmats.2019.00321

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Abstract

A novel dilute Mg-Sn-Mn-Ca (TMX) alloy system was developed and subjected to extrusion with a relatively high extrusion ratio of 36. The grain structure, nanoscale precipitates, texture, and tensile properties of the extruded dilute alloy were investigated. The results indicated that complete dynamic recrystallization (DRX) together with some nanoscale and/or sub-microscale Mg2Sn and Mg2Ca precipitates could be obtained after extrusion. The tensile yield strength, ultimate tensile strength and elongation of the extruded dilute alloy were 213 and 266 MPa, and 21%, respectively. The correlation between microstructural characteristics and properties was also discussed.

Highlights

It is generally accepted that Mg-Sn-based alloys have better strength and ductility than commercial Mg-Al-based alloys after extrusion under identical conditions (Park et al, 2016; She et al, 2016; Cheng et al, 2017b; Lu et al, 2018b)
The microscopic texture of the as-extruded sample was measured at a step size of 1.4 μm using a field-emission scanning electron microscope (Carl Zeiss CrossBeam 1540EsB) equipped with an electron backscatter diffraction (EBSD) detector operating at 20 Kv and HKL Channel 5 acquisition software
Some low angle grain boundaries indicated by laurel-green line could be observed, which indicated that the dynamic recrystallization (DRX) mechanism for the studied alloy is continuous DRX dominated

Summary

Introduction

It is generally accepted that Mg-Sn-based alloys have better strength and ductility than commercial Mg-Al-based alloys after extrusion under identical conditions (Park et al, 2016; She et al, 2016; Cheng et al, 2017b; Lu et al, 2018b). A system of Mg-Sn-based alloys with high Sn content, containing thermally stable Mg2Sn phase has exhibited an excellent extrudability (Sasaki et al, 2008; Cheng et al, 2010). The extruded Mg-Sn-based alloys with high Sn content commonly have sub-microscale and microscale Mg2Sn particles co-existing at the grain boundary in the form of network, which prevents further performance improvement (Cheng et al, 2010). Studies have recently been concentrated on micro-alloyed systems with low content of Sn in order to reduce the cost of products (Chai et al, 2019a). Studies have recently been concentrated on micro-alloyed systems with low content of Sn in order to reduce the cost of products (Chai et al, 2019a). She et al (2016) proposed that the addition of 1 wt.% Sn content in Mg alloys is expected to exhibit a great balance between strength and ductility

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Results

Conclusion