Effect of zirconium on the microstructure and mechanical properties of long period stacking ordered Mg96Gd3Zn1 alloy

Wang

Materials and Corrosion

et al. 2014

The effect of eutectic structure and long period stacking ordered (LPSO) structure on the corrosion resistance of Mg 95.5 Gd 3.5 Zn 1 alloy has been investigated. The eutectic structure and LPSO phase were obtained by different heat treatments and their corrosion behavior and microstructures were examined by immersion test, electrochemical measurement, and SEM. It is suggested that the Mg 95.5 Gd 3.5 Zn 1 alloy containing LPSO phase has a better corrosion resistance than that without LPSO phase. This is due to the smaller accelerating corrosion effect, which is caused by the contact between a-Mg and LPSO phase. Figure 4. Cross-sectional SEM images of corroded surface after immersed in 0.17 M NaCl solution for 18 h: (a) aged Mg 95.5 Gd 3.5 Zn 1 alloy with LPSO phase and (b) as-cast Mg 95.5 Gd 3.5 Zn 1 alloy with eutectic structureFigure 5. Polarization curves of the as-cast and aged Mg 95.5 Gd 3.5 Zn 1 alloys in 0.17 M NaCl solution at room temperature www.matcorr.com

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The relation between microstructure and corrosion behavior of Mg-Gd-Zn alloy with long period stacking ordered structure

Wang

Materials and Corrosion

et al. 2014

Materials Science and Engineering: A

“…Li et al attempted to add the Mn element in Mg-2.5Zn-2.5Y (at.%) alloy and observed the higher area fraction of LPSO phases with increasing the Mn content [28]. Recently, Zhang et al reported that the new precipitations can be induced, and the morphology and distributions of LPSO phases are also varied by incorporating Zr element in Mg-Gd-Zn alloys [29]. In particular, the Sr element is an effective grain refinement element in Mg alloy and can reduce the stacking fault energy of α-Mg matrix [30].…”

Section: Introductionmentioning

confidence: 99%

On the microstructure and mechanical property of as-extruded Mg-Gd-Y-Zn alloy with Sr addition

Liu

Diao

Chai

et al. 2017

In this study, microstructure evolutions of 0.2, 0.6) alloys (named as sample 0Sr, 0.2Sr, 0.6Sr) during heat-treatment and extrusion were investigated. As-cast sample 0Sr contains typical long period stacking ordered (LPSO) phases and Mg 3 RE. With Sr addition, amounts of LPSO phases decrease and are gradually replaced by the Mg 17 Sr 2 phases. After homogenization and annealing treatment, profuse strip LPSO phases readily precipitate in grain interiors of sample 0Sr, while only Mg 17 Sr 2 and Mg 3 RE phases are detected in samples 0.2Sr and 0.6Sr. It suggests that the Sr addition would inhibit LPSO phases. After extrusion, the bimodal grain structures, the bulk and strip LPSO phases are detected in sample 0Sr, which can contribute to providing strengthening and extra strain hardening. In as-extruded sample 0.2Sr, finer recrystallized grain size, bulk Mg 17 Sr 2 and LPSO phases (micron-scale) and Mg 5 RE phase (nano-scale) are found due to the pre-annealing treatment. However, lower amounts of both nano-sized and macro-sized LPSO phases lead to the low ultimate strength (300 MPa). In sample 0.6Sr, the strip LPSO phases are readily formed even though the length and total amounts of LPSO phases decrease.More bulk Mg 17 Sr 2 phases and LPSO phases are also precipitated, which lead to the more superior yield and ultimate strengths of 0.6Sr sample under higher temperature, as compared with the 0Sr sample.2

Effect of Ti and Zr Combined Modification on Microstructures and Mechanical Properties of Mg₉₅Y_2.5Zn_2.5 Alloy Containing LPSO and W Phases

et al. 2017

Adv Eng Mater

In order to develop a high performance Mg-Y-Zn alloy containing LPSO phase in the condition of lower Y/Zn atomic ratio, the effect of Ti and Zr on microstructures and mechanical properties of Mg 95 Y 2.5 Zn 2.5 alloy was investigated. Although the a-Mg grains can be refined by adding Ti and Zr separately, the best refinement effect can be obtained by the combined addition of them. More importantly, the formation of LPSO phase was promoted by adding them in as-cast Mg 95 Y 2.5 Zn 2.5 alloy. Meanwhile, the growth model of W phase was transformed from divorced eutectic to cooperative eutectic. In this case, the LPSO/W interface became continuous, which degraded the mechanical properties of as-cast alloys. After extrusion, the increased LPSO phase caused by adding Ti and Zr greatly improved the strength of as-extruded alloy.