Evolution of microstructure and mechanical properties of an as-cast Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy processed by high pressure torsion

Sun, Wanting; Xu, Chao; Qiao, Xiaoguang; Zheng, M.Y.; Kamado, Shigeharu; Gao, Nong; Starink, M.J.

doi:10.1016/j.msea.2017.05.115

Cited by 36 publications

(39 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, the solute content of the α-Mg remains reasonably constant and causes no supplementary hardening. There is evidence for such solution hardening in an Mg-Gd-Y-Zn-Zr alloy after HPT processing [68]. Furthermore, this research also revealed a mechanism of dispersion hardening by which the Mg-RE intermetallics in the Mg-Gd-Y-Zn-Zr alloy were broken into small particles with sizes of ~1-10 μm and were then homogeneously dispersed in the matrix after HPT for 16 turns [68].…”

Section: Hardness Evolutionmentioning

confidence: 67%

Texture and microhardness of Mg-Rare Earth (Nd and Ce) alloys processed by high-pressure torsion

Bourezg

Azzeddine

Baudin

et al. 2018

Materials Science and Engineering: A

View full text Add to dashboard Cite

The influence of high-pressure torsion (HPT) processing on the texture and microhardness of two binary Mg-RE (RE=Nd and Ce) alloys was investigated using X-ray diffraction and Vickers microhardness measurements. Disks cut from the alloys were processed by HPT at room temperature for up to 10 turns. The precipitation products of both alloys were identified using synchrotron radiation. The results show that both alloys exhibit a weak basal texture where the c-axis of most grains is shifted 15° from the shear direction. An Mg-1.44Ce (wt. %) alloy showed a continuous decrease in the texture strength which may be due to the effect of second precipitation phases (Mg 17 Ce 2 and MgCe 2). The microhardness of both alloys increased significantly with increasing HPT turns but levelled-off beyond about one HPT turn. Maximum values of ~65 and ~96 Hv were achieved which are significantly higher than the hardness of the undeformed Mg-Ce and Mg-Nd alloys.

show abstract

Section: Hardness Evolutionmentioning

confidence: 67%

Texture and microhardness of Mg-Rare Earth (Nd and Ce) alloys processed by high-pressure torsion

Bourezg

Azzeddine

Baudin

et al. 2018

Materials Science and Engineering: A

View full text Add to dashboard Cite

show abstract

“…Amongst SPD techniques, high pressure torsion (HPT) processing has the potential for achieving the greatest grain refinement at room temperature by using extremely large torsional straining and high hydrostatic pressure to prevent cracking. SPD has also been applied to refine and disperse second phases effectively in different alloys, such as Mg alloys, Al alloys and pearlitic steels [21][22][23][24]. The evolution of the second phase particles during SPD depends on various factors such as their size, morphology and also the processing parameters.…”

Section: Introductionmentioning

confidence: 99%

Evolution of long-period stacking ordered structure and hardness of Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy during processing by high pressure torsion

Sun

Qiao

Zheng

et al. 2018

Materials Science and Engineering: A

Self Cite

View full text Add to dashboard Cite

High pressure torsion (HPT) was performed at room temperature on a Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr (wt.%) alloy containing long period stacking ordered (LPSO) phase with a 6.0 GPa pressure. The microstructure evolution and hardening mechanisms were analyzed. TEM shows that, with increasing HPT strain, the LPSO lamellar-shaped and block-shaped particles experience kink bending, fragmentation and dissolution; and eventually a supersaturated solid solution with nanosized grains is obtained. The decomposition of LPSO phase at room temperature is attributed to the high defect concentrations generated in the LPSO lamellae and blocks, and the Mg-rich phase. With equivalent strains increasing to ~6.6 (16 HPT revolutions), an exceptional grain refinement to 52±2 nm is achieved, and the hardness is enhanced to 128±2 HV. A quantitative model shows the hardness increase is due to the combined effects of nanosized grains, high dislocation density and dissolved alloying elements. XRD line broadening analysis, thermodynamic modelling software and elemental mapping are used to support the mechanistic interpretations.

show abstract

“…To obtain strong age hardening effect, a multi-element Mg-Y-Gd-Zn-Zr alloy was employed. This alloy system has been proved to exhibit obvious aging effect by various precipitates and contains LPSO phase as well, which showed great potential for industrial applications as a promising high-performance magnesium alloy [23,32,33]. In the present work, we prepared an UFG Mg-10Y-6Gd-1.5Zn-0.5Zr alloy via multi-pass ECAP first and then comparatively investigated the effects of two kinds of aging treatments (T5 and T6) on precipitation behaviors, microstructure evolutions and mechanical properties of the UFG alloy.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of Two Aging Treatments on Microstructure and Mechanical Properties of an Ultra-Fine Grained Mg-10Y-6Gd-1.5Zn-0.5Zr Alloy

Liu

Huang

et al. 2018

Metals

View full text Add to dashboard Cite

Developing high strength and high ductility magnesium alloys is an important issue for weight-reduction applications. In this work, we explored the feasibility of manipulating nanosized precipitates on LPSO-contained (long period stacking ordered phase) ultra-fine grained (UFG) magnesium alloy to obtain simultaneously improved strength and ductility. The effect of two aging treatments on microstructures and mechanical properties of an UFG Mg-10Y-6Gd-1.5Zn-0.5Zr alloy was systematically investigated and compared by a series of microstructure characterization techniques and tensile test. The results showed that nano γ" precipitates were successfully introduced in T5 peak aged alloy with no obvious increase in grain size. While T6 peak aging treatment stimulated the growth of α-Mg grains to 4.3 µm (fine grained, FG), together with the precipitation of γ" precipitates. Tensile tests revealed that both aging treatments remarkably improved the strengths but impaired the ductility slightly. The T5 peak aged alloy exhibited the optimum mechanical properties with ultimate strength of 431 MPa and elongation of 13.5%. This work provided a novel strategy to simultaneously improve the strength and ductility of magnesium alloys by integrating the intense precipitation strengthening with ductile LPSO-contained UFG/FG microstructure.

show abstract

Evolution of microstructure and mechanical properties of an as-cast Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy processed by high pressure torsion

Cited by 36 publications

References 42 publications

Texture and microhardness of Mg-Rare Earth (Nd and Ce) alloys processed by high-pressure torsion

Texture and microhardness of Mg-Rare Earth (Nd and Ce) alloys processed by high-pressure torsion

Evolution of long-period stacking ordered structure and hardness of Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy during processing by high pressure torsion

Comparative Study of Two Aging Treatments on Microstructure and Mechanical Properties of an Ultra-Fine Grained Mg-10Y-6Gd-1.5Zn-0.5Zr Alloy

Contact Info

Product

Resources

About