Provided is a magnesium alloy having high strength and high thermal conductivity containing a atom % of Zn and b atom % of Y, a remainder consisting of Mg and unavoidable impurities, where a and b satisfy formulas 1 to 8. The magnesium alloy contains an Mg.sub.3Zn.sub.3Y.sub.2 phase or both an Mg.sub.3Zn.sub.3Y.sub.2 phase and an Mg.sub.3Zn.sub.6Y phase and does not contain a long period stacking ordered phase. (Formula 1) a=0.5 (0.25b1.2) (Formula 2) b=1.2 (0.5a1.62) (Formula 3) a=1.35b (1.2b3) (Formula 4) b=3 (4.05a7) (Formula 5) a=7 (0.25b3) (Formula 6) b=0.25 (0.5a7) (Formula 7) a=4.2b+0.7 (0.25b1.5) (Formula 8) b=0.25 (0.5a1.75).

A die-casting aluminum alloy without heat-treatment and a preparation method and application thereof. Based on a total weight of the die-casting aluminum alloy, the die-casting aluminum alloy includes: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.8 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.8 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.

A molten metal laundering system includes a pump that draws molten metal from a reservoir. A heated raceway receives the molten metal from the pump and carries a flow of the molten metal. A conduit extends from the heated raceway and is exposed exterior the heated raceway. The conduit carries the flow. A temperature sensor senses a temperature of the molten metal in the conduit. An outlet at an end of the conduit directs the flow from the conduit into a casting mold. A flow meter is disposed along the conduit with the conduit extending through the flow meter. The flow meter senses a flow rate of the flow of the molten metal in the conduit. A control module adjusts operation of the pump based at least on the flow rate sensed by the flow meter and the temperature sensed by the temperature sensor.