Preparation method of nano-particle reinforced magnesium-based composite material

The invention provides a preparation method of a nano-particle reinforced magnesium-based composite material. The method comprises the following steps: adding a matrix alloy raw material into a crucible, starting argon protection, and heating and melting the raw material along with a furnace in an argon protection environment; wherein the inner cavity of the crucible is of a frustum-shaped structure with a thick upper part and a thin lower part; cooling the melt until the melt is in a semi-solid state, continuously stirring the semi-solid melt by adopting a stirrer, and uniformly spraying argon and nano-particles into the melt from multiple angles; and heating the melt to a pouring temperature, then pouring the melt into a preheated mold, and carrying out directional solidification to obtain a nano-particle reinforced magnesium-based composite material cast ingot. According to the method disclosed by the invention, the purpose of rapidly, smoothly and uniformly introducing the nano-particles into the magnesiu