Recent research and developments on wrought magnesium alloys

Emerging trends in manufacturing such as light weighting, increased performance and functionality increases the use of multi-material, hybrid structures and thus the need for joining of dissimilar materials. The properties of the different materials are jointly utilised to achieve product performance. The joining processes can, on the other hand be challenging due to the same different properties. This paper reviews and summarizes state of the art research in joining dissimilar materials. Current and emerging joining technologies are reviewed according to the mechanisms of joint formation, i.e.; mechanical, chemical, thermal, or hybrid processes. Methods for process selection are described and future challenges for research on joining dissimilar materials are summarized.

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Joining of dissimilar materials

Hall-Petch relationship in Mg alloys: A review

Friction stir welding/processing of metals and alloys: A comprehensive review on microstructural evolution

Friction stir based welding and processing technologies - processes, parameters, microstructures and applications: A review

Influence of grain size and texture on Hall–Petch relationship for a magnesium alloy

Effect of Tool Design and Process Parameters on Properties of Al Alloy 6016 Friction Stir Spot Welds

Effect of texture on the mechanical behavior of ultrafine grained magnesium alloy

Cold rolled AZ31 magnesium alloy sheet was subjected to friction stir processing to generate four average grain sizes ranging from 0.8 to 9.6 μm. The processed material exhibited a strong basal fiber texture with the c -axis tilted about 35–55° towards the processing direction. The grain size and texture dependence of mechanical behavior were evaluated by using tensile testing along two orthogonal directions. Remarkably high ductility of ∼65% was achieved in relatively coarse grained material that fractured without developing necking when tested in the processing direction. The ductility decreased significantly to ∼10% for ultrafine grained material as the tensile yield strength increased from ∼53 MPa to ∼180 MPa. Grain size had limited influence on ductility of processed material tested in transverse direction, but reduced the uniform elongation to ∼2% for ultrafine grained material which exhibited ∼320 MPa yield strength. Accompanying the significant anisotropy in tensile strength in two directions, the deformation of processed AZ31 in the processing direction was mainly accommodated through basal slip and extension twinning (except for ultrafine grained material); however, the deformation of material in transverse direction was dominated by non-basal slip. Influences of grain size and texture on mechanical behavior were studied in terms of work-hardening and deformation mechanisms.

Grain size and texture effects on deformation behavior of AZ31 magnesium alloy

Friction stir processing of a rolled AZ31 alloy and a high pressure die cast AZ91 alloy produced ultrafine grained materials with average grain size of 0.8 μm and 0.5 μm, respectively. Tensile testing was done in the temperature range of 210–360 °C and strain rate range of 1×10 −4 –3×10 −2  s −1 . Higher amounts of β-precipitates in AZ91 thermally stabilized the microstructure up to 330 °C. Friction processed ultrafine grain AZ91 exhibited high strain rate superplasticity at all tested temperatures. The best elongation of 1251% was achieved at a strain rate of 1×10 −2  s −1 and temperature of 330 °C. The kinetic analysis of the superplastic data revealed a large variation in the kinetic parameter due to difficulty in using proper grain size values because of concurrent grain growth.

Wei Yuan

Papers

Influence of grain size and texture on Hall–Petch relationship for a magnesium alloy

Effect of Tool Design and Process Parameters on Properties of Al Alloy 6016 Friction Stir Spot Welds

Effect of texture on the mechanical behavior of ultrafine grained magnesium alloy

Grain size and texture effects on deformation behavior of AZ31 magnesium alloy

High strain rate superplasticity in friction stir processed ultrafine grained Mg–Al–Zn alloys