Preparation method of aluminum magnesium alloy for automobile transmission

The invention relates to a preparation method of aluminum magnesium alloy for an automobile transmission. The preparation method comprises the steps that aluminum, magnesium, nickel and cobalt particles are smelted, dross is thoroughly taken out to obtain alloy liquid after dissolved clarification; the alloy liquid drops onto the surface of a red copper wheel rotating at high speed to be thrown out, and cooling is performed to obtain an alloy belt; the alloy belt is ball-grinded to obtain alloy powder; the alloy powder is put in an extrusion die, and then extrusion forming is performed through an extrusion machine to obtain an alloy material; the alloy material is subjected to sintering and heat treatment; then the material subjected to the heat treatment and the liquid are mixed to obtain metal powder slurry; then the slurry is made into spherical metal powder for 3D printing through a mist spraying pelletizer. It can be ensured that the metal staying time at a high-temperature stage is shorter, alloy elements are too late to diffuse, accordingly tissues are refined, segregation is reduced, material strength is improved through an extrusion and heat treatment process, and then higher-strength metal powder can be prepared through the mist spraying pelletizer.