Precipitation and its effect on the mechanical properties of a cast Mg–Gd–Nd–Zr alloy

Effect of precipitates on microstructures and properties of forged Mg–10Gd–2Y–0.5Zn–0.3Zr alloy during ageing process

“…→ ␤ → ␤ → ␤ 1 (fcc) → ␤(fcc), which was confirmed by other researchers [6][7][8][9]. The ␤ and ␤ phases precipitating at the early stage of ageing process are main strengthening phases for Magnesium alloys [6,10]. The metastable ␤ phase has a D0 19 crystal structure (hexagonal, a = 0.642 nm, c = 0.521 nm) and intermediate ␤ phase has a base-centered orthorhombic structure (a = 0.640 nm, b = 2.223 nm, c = 0.521 nm).…”

“…7(c) and (d), which suggests that the crystal parameters of ␤ phase are: a = 0.640 nm, b = 2.223 nm, c = 0.521 nm[10]. Some clusters of diffraction spots appear between central point and [0 11 0]˛which confirms three variants of ␤ phase around [0 0 0 1] ␣ zone.…”

“…The evolution of grain boundary structure is accompanied by two coinstantaneous procedures: growing of precipitates at grain boundary and widening of precipitates free zones (PFZ) [10]. The metastable phase dissolves into the matrix in order to lower energy and solute atoms disperse to the grain boundaries with formation of the soft PFZ.…”

“…The precipitate behavior of main strengthening phases in Magnesium alloys containing rare earth during ageing process has been studied for years and some results have been put forward by many researchers [4][5][6][7][8][9][10][11][12]. It was reported that the precipitation sequence for binary Mg-Y alloy is: supersaturated solid solution (S.S.S.S.)…”

The Microstructures and Tensile Properties of As-Extruded Mg–4Sm–xZn–0.5Zr (x = 0, 1, 2, 3, 4 wt %) Alloys

“…Rare earth (RE) metals have been proved to play an important role in improving mechanical properties of Mg alloys [4]. There has been a great deal of research on 1Mg-Y [5][6][7][8], Mg-Gd [9][10][11][12][13] and Mg-Nd [14] alloys, and some of the alloys exhibit good mechanical properties at elevated temperature. As one of the light rare earth elements, Sm has a maximum solubility of about 5.8 wt %, which even is higher than that of Nd (3.6 wt %) in solid Mg.…”