The study developed the three alloy systems with different precipitates and examined the role of precipitated phase particles in modifying the creep properties of as-cast Mg-10Bi-0.5Mn-0.5Ag (BMQ1000), Mg-5Bi-5Sn-0.5Mn-0.5Ag (BTMQ5500) and Mg-10Sn-0.5Mn-0.5Ag (TMQ1000) alloys at temperatures ranging from 423 to 473 K and stresses of 45–85 MPa. The values of n for the BMQ1000, BTMQ5500, and TMQ1000 alloys were determined as 6.67, 5.75, and 5.92, respectively. Moreover, the activation energy for these alloys was found to be 164.71, 134.68, and 135.93 kJ/mol, respectively. The results suggested that the creep properties followed the order of BTMQ5500 > TMQ1000 > BMQ1000. A coarse and uneven distribution of the Mg₃Bi₂ precipitated phase in the BMQ1000 alloy leads to a feeble pining effect on dislocation slipping and generates substantial stress concentrations. For TMQ1000 alloy, while the nanoscale Mg₂Sn precipitates have a stronger barrier effect on dislocations than the Mg₃Bi₂ in the BMQ1000 alloy, their ability to inhibit dislocation climbing is comparatively weak. Furthermore, it was found that Mg₂Sn precipitates and α-Mg exhibited a preferential orientation relationship of (020)_Mg2Sn // (–1010)_Mg, and the morphology of the precipitated phase transformed in a way that hinders dislocation movement effectively. In addition, elastic interactions between the precipitated phases are identified. The above-mentioned factors are largely responsible for the notable enhancement in creep resistance. Further, it is ascertained that cross-slip and pyramidal 〈c + a〉 slip are primary creep mechanisms in the BMQ1000 alloy. In contrast, the dominant mechanisms in TMQ1000 and BTMQ5500 alloys are dislocation climb and pyramidal 〈c + a〉 slip. Moreover, stacking faults (SFs) and twinning assist in the creep deformation of the BTMQ5500 alloy.

The influence of micro-Ca/In alloying on the microstructural characteristics, electrochemical behaviors and discharge properties of extruded dilute Mg-0.5Bi-0.5Sn-based (wt.%) alloys as anodes for Mg-air batteries are evaluated. The grain size and texture intensity of the Mg-Bi-Sn-based alloys are significantly decreased after the Ca/In alloying, particularly for the In-containing alloy. Note that, in addition to nanoscale Mg₃Bi₂ phase, a new microscale Mg₂Bi₂Ca phase forms in the Ca-containing alloy. The electrochemical test results demonstrate that Ca/In micro-alloying can enhance the electrochemical activity. Using In to alloy the Mg-Bi-Sn-based alloy is effective in restricting the cathodic hydrogen evolution (CHE) kinetics, leading to a low self-corrosion rate, while severe CHE occurred after Ca alloying. The micro-alloying of Ca/In to Mg-Bi-Sn-based alloy strongly deteriorates the compactness of discharge products film and mitigates the "chunk effect" (CE), hence the cell voltage, anodic efficiency as well as discharge capacity are greatly improved. The In-containing alloy exhibits outstanding discharge performance under the combined effect of the modified microstructure and discharge products, thus making it a potential anode material for primary Mg-air battery.

The creep properties, microstructural characteristics and creep mechanisms of as-cast Mg-5Bi-5Sn (BT55) alloy without and with Mn (BTM550) addition were investigated via creep at 423, 448, and 473 K as well as stresses of 30, 50 and 75 MPa. The results indicate that adding Mn can result in the formation of primary and the dynamic precipitated α-Mn phases. In addition, the morphology of the precipitated Mg₃Bi₂ phase and the orientation relationship between Mg₂Sn precipitates and α-Mg can be effectively modified. Tailoring the microstructural characteristics is responsible for the improved creep performance of BTM550 alloy. The dominant creep mechanisms in BT55 and BTM550 alloys are dislocation cross-slip and climb, respectively. Furthermore, twinning and pyramidal 〈c + a〉 slip play an assisting part in both alloys during creep process.