Aluminum-copper alloy, also called hard aluminum alloy, can be heat-treated and aging-strengthened. It has high room temperature strength and good high-temperature and ultra-low temperature performance. Therefore, aluminum-copper alloy is one of the metal structural materials widely used in industry. Among the aluminum-copper series alloys, most of the alloys have poor welding performance, and the welded joint strength coefficient is only 60% of the base metal, which severely restricts the further application of aluminum-copper alloys in industry. For example, aluminum rare earth alloys have a refining effect on aluminum alloys, thereby inhibiting the growth of columnar crystals and double columnar crystals, and promoting the formation of fine axial crystals. This is the grain refinement treatment. The refined aluminum alloy performance will be improved, and at the same time, the defects such as loosening, hot cracking, and pinholes of the aluminum alloy can be reduced, and the scope of use can be increased. Adding a proper amount of rare earth to the aluminum alloy can not only play the role of grain refinement, but also significantly refine the dendritic structure, and only under a certain production process can it achieve the best refinement effect. The refined aluminum alloy properties will continue to change, can be used in domestic industrial production, and outstanding performance.
