Microstructure and tensile creep behavior of Mg–4Al based magnesium alloys with alkaline-earth elements Sr and Ca additions

Microstructural characterization of Mg–Al–Sr alloys

“…Baril et al [11] investigated four samples in the Mg-rich region of the Mg-Al-Sr system and tentatively designated a ternary phase as Al 3 6 Sr 60 reported by Makhmudov et al [8]. Jing et al [12] recently investigated the microstructure and tensile creep behavior of Mg-Al-Sr (AJ) based alloys and reported that a ternary interphase exists in the alloys containing 2-3 wt% Sr at the grain boundaries. Czerwinski and Zielinska-Lipiec [13] investigated the microstructural evolution of a Mg 5 Al 2 Sr (wt%) alloy and reported that the common feature of Sr-containing phases in the as-cast ingots is their location at grain or sub-grain boundaries.…”

Microstructure and Mechanical Properties of Mg-Al-Ca-Nd Alloys Fabricated by Gravity Casting and Extrusion Process

“…In the recent, B. Jing et al reported that these fine intermetallic compounds in -Mg matrix were close to that of (Mg, Al) 2 Ca compound. 7) In this microstructure of as-cast alloys, these two kind of (Mg, Al) 2 Ca phases were observed: coarse irregular-shape structure at grain boundary and fine needle-shape structure in the -Mg matrix grain. For commercial Mg-Al based alloys, such as AZ and AM series alloys, the (Mg 17 Al 12 ) phase commonly appears in as-cast microstructure and is considered as the main strengthening effect on the alloys at room temperature.…”

“…The main design concepts for attaining high temperature properties include solid-solution strength and grain boundary strength by intermetallic compounds to suppress the local deformation and/or sliding in the vicinity of grain boundaries. Among the alloy element described above, Ca is a promising elemental addition for the following reasons: [5][6][7][8][9][10] (1) the addition of Ca significantly improves the high temperature strength and creep resistance; (2) further improvement is possible with quaternary addition; and (3) it has low density and is low cost. Thus, the Mg-Al-Ca ternary system is one of the most important systems for further alloy development.…”

The Effects of Yttrium Element on Microstructure and Mechanical Properties of Mg-5 mass%Al-3 mass%Ca Based Alloys Fabricated by Gravity Casting and Extrusion Process

“…In the recent, B. Jing et al reported that these fine intermetallic compounds in -Mg matrix were close to that of (Mg, Al) 2 Ca phases. 7) As shown in Fig. 1(b), the coarse intermetallic compounds with bright contrast were identified to Al 2 Y phase by SEM-EDX analysis (Fig.…”

“…It is well known that alloys of Mg-Al-Ca systems may provide significant improvement in elevated temperature properties due to reduction of volume fraction of Mg 17 Al 12 phase. [5][6][7][8][9][10] Moreover, it has been reported that the content variation of rare earth elements (RE) and element Y in the magnesium alloys can influence the mechanical properties greatly, [11][12][13][14][15][16] which is mainly ascribed to the Orowan mechanism. 17,18) And, high performance Mg-Zn based alloys containing Y have been developed by Kawamura et al 19) This alloy with Y addition, prepared by extrusion process, reveals excellent mechanical properties including maximum tensile yield strength about 600 MPa and elongation about 5% at room temperature.…”