High-toughness aluminum lithium alloy and preparation method thereof

Abstract

The invention discloses a high-toughness aluminum lithium alloy and a preparation method thereof. The alloy comprises the following chemical components in percentage by weight: 3.2 to 4.2 percent of Cu, 0.7 to 1.8 percent of Li, 0.20 to 0.60 percent of Mn, 0.20 to 0.60 percent of Zn, 0.06 to 0.20 percent of Zr, 0.20 to 0.80 percent of Mg, 0.2 to 0.7 percent of Ag, less than or equal to 0.10 percent of Si, less than or equal to 0.10 percent of Fe, less than or equal to 0.12 percent of Ti, less than or equal to 0.15 percent of other impurities (single impurity is less than or equal to 0.05 percent) and the balance of Al. One or five of alloy elements Mn, Zn, Mg, Ag and Zr can be selectively added. Proportioning is performed according to the alloy components, the raw materials are melted, then furnace refining and standing are performed, and alloy ingots with required specifications are cast. The alloy ingots are preferably homogenized and then molded by any process of hot extruding, hot rolling and the like, and the alloy ingots thermally treated by the preferable process can be used for processing parts. The high-toughness aluminum lithium alloy material has uniform microscopic structure and stable performance, and is suitable for manufacturing thick plates and extruded materials. The ultimate tensile strength can reach over 510MPa, and meanwhile, the elongation rate is more than 8 percent and the KIc can reach over 30MPam1 / 2. The material product can be used for structural elements of the fields of aerospace, nuclear industry, traffic and transportation, sports goods, weapons and the like.

Description

Technical field [0001] The invention is a high-strength aluminum-lithium alloy and a preparation method thereof, which belongs to the field of metal material engineering. Background technique [0002] In recent years, with the improvement of aluminum metallurgical equipment technology and basic metallurgical technology, aluminum-lithium alloys have experienced three generations of development. The metallurgical design principles of aluminum-lithium alloys have developed into: moderate strength, slightly lower density, and low anisotropy. , and give full play to its rigidity and damage resistance advantages. The pursuit of lower process costs in production means that its production process is closer to that of ordinary aluminum alloys. [0003] As competition in the aviation industry, especially in the civilian large aircraft manufacturing industry, intensifies, aircraft manufacturing companies such as Boeing, Airbus, Bombardier and COMAC have taken economic operation and lo...

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Problems solved by technology

[0007] The anisotropy of Al-Li alloys comes from the coplanar slip and texture caused by the δ′ phase, and the addition of Zr can inhibit the coplanar slip of the δ′ phase and have a good toughening effect on the alloy, but The anisotropy of the alloy cannot be greatly reduced

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