Carbon nanotube modified Mg-Al-Mn series magnesium alloy material used for casting automobile part and preparing method thereof

The invention relates to the technical field of magnesium alloy preparation and particularly relates to a carbon nanotube modified Mg-Al-Mn series magnesium alloy material used for casting an automobile part and a preparing method thereof. The material belongs to Mg-Al-Mn series high-heat-resistant alloy. As B and Sr two microelements are doped in the material, a remarkable effect of refining the crystal grains of the alloy is realized. Besides, a polyvinylpyrrolidone and absolute ethyl alcohol solution is used as a medium, carbon nanotubes are dispersed in the medium, Mg powder is then added into the dispersion solution, mixed and ground, and the carbon nanotubes are uniformly wrapped and dispersed in the Mg powder. The mixing of the carbon nanotubes with other metal elements in the following smelting process is also more sufficient, a better modifying effect is realized, and the method is more efficient than a traditional agitating and adding process. The dynamic enhancing effect of the prepared magnesium alloy material is remarkable, so that both the machining performance and the use performance of the automobile part prepared from the material are obviously improved. Absolute ethyl alcohol used in the preparing process can also be recycled so as to avoid pollution.