Role of icosahedral phase in enhancing the strength of Mg–Sn–Zn–Al alloy

Kim, Y.K.; Sohn, Seung Kook; Kim, Dowhan; Kim, W.T.; Kim, D.H.

doi:10.1016/j.jallcom.2012.09.050

Cited by 52 publications

(31 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fig. 11 summarizes the yield strengths and elongation to failure of various Mg based wrought alloys fabricated by conventional ingot metallurgy process [2,5,6,[9][10][11]15,16,18,[40][41][42][43][44][45][46][47][48][49][50]. The TZAM6620 alloy developed in this work showed better strength-ductility balance compared to previously studied Mg-Sn based alloys and the other commercially available wrought alloys such as Mg-Al-Zn and Mg-Zn alloys.…”

Section: Discussionmentioning

confidence: 99%

Strong and ductile heat-treatable Mg–Sn–Zn–Al wrought alloys

et al. 2015

View full text Add to dashboard Cite

a b s t r a c tA newly developed Mg-Sn-Zn-Al based alloy shows substantial strengthening by artificial aging. A Na-doped Mg-5.4Sn-4.2Zn-2.0Al-0.2Mn-0.1Na (TZAM5420À0.1Na) (wt.%) alloy exhibited a significant increase in yield strength from 243 to 347 MPa by a T6 treatment due to the uniform dispersion of nanoscale precipitates by aging. The trace addition of Na causes the formation of Sn-Na co-clusters in the early stage of aging, which provides heterogeneous nucleation sites for Mg 2 Sn precipitates. However, Na strongly segregates at grain boundaries and this degrades the ductility significantly. To overcome this problem, we developed a Na-free Mg-6.6Sn-5.9Zn-2.0Al-0.2Mn (TZAM6620) alloy, in which nano-scale MgZn 2 precipitates are uniformly dispersed by double aging. Pre-aging caused the formation of Zn-rich Guinier Preston zones, which acted as heterogeneous nucleation sites for the MgZn 2 precipitates. The double-aged TZAM6620 alloy exhibited a very high yield strength of 370 MPa with large elongation of 14%.

show abstract

Section: Discussionmentioning

confidence: 99%

Strong and ductile heat-treatable Mg–Sn–Zn–Al wrought alloys

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Thus, the decreasing solubility of CO 2 in water with increasing temperature is expected to slow down carbonatiztion at higher temperature. Conversely, the hydration of CO 2 to form carbonic acid is; CO 2 (aq) + H 2 O → H 2 CO 3 (aq) [8] This is a relatively slow, activated process that becomes faster at high temperature, promoting carbonatization. The absence of a clear temperature dependency of the corrosion of Mg together with the strong positive temperature effect reported for NaCl-induced atmospheric corrosion of Al 42 suggests that the slowing of the corrosion of alloy AM50 at low temperature is related to the aluminum content in the alloy.…”

Section: Discussionmentioning

confidence: 99%

“…However, the more widespread use of MgAl alloys is limited by their low corrosion resistance and poor high temperature mechanical properties. [5][6][7][8] The corrosion properties of MgAl alloys have therefore attracted scientific attention. Currently, the majority of Mg-Al cast components are produced by conventional high-pressure die casting (HPDC).…”

mentioning

confidence: 99%

Effect of Rheocasting on Corrosion of AM50 Mg Alloy

Esmaily

Mortazavi

Shahabi-Navid

et al. 2014

J. Electrochem. Soc.

View full text Add to dashboard Cite

The corrosion behavior of magnesium-aluminum (Mg-Al) alloy AM50 produced by a rheocasting (RC) technique was examined in the presence and absence of CO 2 at three temperatures −4, 4 and 22 • C. The slurry preparation in the RC material was performed with the newly developed RheoMetal process. For reference, 99.97% Mg was included in the corrosion exposures. The influence of the microstructure on the atmospheric corrosion of alloy AM50 produced by RC and high pressure die casting (HPDC) was investigated. The RC AM50 alloy showed better corrosion resistance than HPDC AM50 in all the exposure environments studied. For both materials, there was a strong positive correlation between temperature and the atmospheric corrosion rate. The superior atmospheric corrosion behavior of RC AM50 compared to HPDC AM50 is carefully discussed in relation to differences in the as-cast microstructure. This study demonstrates that producing the alloy AM50 by this type of RC technique opens the door to Mg-Al alloys as a promising candidate for various applications where corrosion resistance is of importance. Magnesium-aluminum (Mg-Al) alloys are being employed in the automotive and many other engineering sectors owing to their high specific strength, high specific stiffness, good castability and recycleability, excellent machinability and abundant resources.1-4 Thus, they offer several advantages from the weight reduction and energy savings points of view. However, the more widespread use of MgAl alloys is limited by their low corrosion resistance and poor high temperature mechanical properties. [5][6][7][8] The corrosion properties of MgAl alloys have therefore attracted scientific attention. Currently, the majority of Mg-Al cast components are produced by conventional high-pressure die casting (HPDC). One of the main problems of thickwalled Mg-Al components made by HPDC is the relatively high fraction of porosity caused by the turbulent die filling. The pores function as local stress concentrators and can severely degrade mechanical properties and porosity also interferes with the heat-treatment of cast components. 9,10 Semi-solid casting is an alternative manufacturing technique that can be used to produce castings with a high level of complexity. In this process, a semi solid slurry is used, which shows non-turbulent or thixotropic flow behavior. Semi-solid cast alloys offer some advantages over their HPDC counterparts. For instance, porosity is lower due to laminar mould-filling and lower solidification shrinkage. 11,12Thixo-forming and rheocasting (RC) are the main semi-solid manufacturing processes. In thixo-forming, a near-net shape forming process is achieved using a partially melted, non-dendritic alloy slug. 12In contrast, RC involves preparation of a semi-solid slurry from the liquid alloy by cooling. In the RheoMetal process (also called the RSF process or the Rapid S process) cooling is performed by using an enthalphy exchange material (EEM) attached to a stirrer. 13 Thus, the metal is cooled internally which eliminates t...

show abstract

“…9 Additionally, alloying elements such as Zn and/or Al have been proved to be effective in improving mechanical properties by grain refinement and precipitation hardening. 10,11 Recently, Kim et al 12 have reported that an Mg 47.2 Zn 36.9 Al 15.9 icosahedral quasicrystal phase (I-phase) could be obtained by selecting a suitable Zn/Al mass ratio in the Mg-Sn alloy system. The I-phase was solubilized in a-Mg after homogenization and would reprecipitate during the subsequent hot deformation process, resulting in a significant increase in strength.…”

Section: Introductionmentioning

confidence: 99%

Microstructures and mechanical properties of as-ECAPed Mg–8Sn alloys with the combined addition of Zn and Al

et al. 2017

View full text Add to dashboard Cite

A "RE-free" and I-phase-containing Mg-8Sn-based alloy system was developed and successfully fabricated through the equal channel angular pressing (ECAP) process. The influence of the Zn/Al mass ratio on the microstructures and mechanical properties of the as-ECAPed Mg-8Sn-(5,6,7) Zn-2(wt%)Al alloys was investigated using an optical microscope, an X-ray diffractometer, a scanning electron microscope, a transmission electron microscope, and a universal testing machine. Grain size, dynamic recrystallization behavior, and texture were found to be greatly affected by the Zn/Al mass ratio. Furthermore, the ultimate tensile strength (250 MPa) and elongation (14.5%) of the alloy with a Zn/Al mass ratio of 3 were considerably increased compared to those of the as-ECAPed alloys with Zn/Al ratios of 2.5 and 3.5 (ultimate tensile strength and elongation of 215 MPa and 13% and 184 MPa and 10%, respectively). This significant enhancement was attributed to extensive grain boundary strengthening, precipitation strengthening, and higher work hardening capacity as well as texture randomization. The strength and ductility of the as-ECAPed alloys are also discussed in terms of the I-phase and Mg 2 Sn formation.

show abstract

Role of icosahedral phase in enhancing the strength of Mg–Sn–Zn–Al alloy

Cited by 52 publications

References 35 publications

Strong and ductile heat-treatable Mg–Sn–Zn–Al wrought alloys

Strong and ductile heat-treatable Mg–Sn–Zn–Al wrought alloys

Effect of Rheocasting on Corrosion of AM50 Mg Alloy

Microstructures and mechanical properties of as-ECAPed Mg–8Sn alloys with the combined addition of Zn and Al

Contact Info

Product

Resources

About