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%.
Permanent mold casting is a well-established route for casting large magnesium alloys components. Casting parameters like superheat, mold temperature, and holding time can often result in inhomogeneous properties, porosity, and segregation problems in the cast part. In order to optimize the casting process, control of the casting parameters including mold temperatures and holding times is essential to promote directional solidification, and ensure defect free homogenous structure. Binary Mg-9wt.%Al and Mg-10wt.%Gd alloys were used to investigate the effect of casting parameters such as melt temperature and holding time on the part macro and microstructure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.