Precipitation processes in a Mg–Zn–Sn alloy studied by TEM and SAXS

Size control of Sb2Te3 Widmanstätten precipitates in thermoelectric PbTe

“…Such a coarsening behavior of precipitates is considered to originate from a capillary effect as has been recognized for a number of cases for other alloy systems. Coarsening kinetics of plate precipitates has been studied both experimentally and theoretically by several research groups [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. Boyd and Nicholson [32] has first derived the time evolution of average disc diameter, d P , as:…”

“…For plate precipitates, a t 1/3 rule such as Eq. (7) described the time evolution of the diameter of plates well in some cases [32,36,44,53] but fails in others [37,43,46]. As Zocco and Plichta [40] pointed out, the coarsening processes of the structure consisting of plate precipitates is more complicated than those of spherical precipitates since there are two ripening processes: (1) coarsening of individual precipitates towards equilibrium shape; and (2) coarsening in size.…”

“…Therefore, instead of n = 3 (Eq. (7)) we fit a semi-emperical equation with a variable exponent n to the time dependence of the average plate diameter following Rashkova et al [46]. This fitting results in n $ 8.5.…”

Effect of Ca addition on the as-cast microstructure and creep properties of Mg-5Zn-5Sn magnesium alloy

“…At present, efforts are being made towards developing new creep-resistant magnesium alloys based on Mg-Zn-Sn system due to the following reasons [3]: (1) Zn can enhance the age hardening response and improve the castability, and has several stable intermetallics with Mg; (2) Sn not only can improve corrosion resistance but also can form a stable Mg 2 Sn compound with Mg. From recent investigations [4][5] the Mg-5Zn-5Sn alloy has been identified as one of the most promising magnesium alloys. According to the reported investigation results [6][7], the strengthening mechanism of Mg-5Sn-5Zn alloy is mainly related with the formation of two types of precipitates MgZn and Mg 2 Sn. However, it is further reported that the relatively poor structural stability of the alloy at high temperatures results in poor creep properties thus restricting the utilization of the alloy.…”

Characterising precipitate evolution in multi-component cast aluminium alloys using small-angle X-ray scattering

“…Thus, this technique provides quantitative and statistically reliable results including average precipitate size, volume fraction, number density and, potentially, precipitate size distribution (PSD). The application of SAXS for measuring the sizes of nanoscale precipitates in a range of metallic systems is well established, especially on binary and ternary systems [10][11][12][13][14]. Most previous studies of precipitation phenomena in aluminium alloys by SAXS have been conducted on precipitationhardened wrought alloys analogues, such as Al-Cu and Al-Mg-Si.…”