There are several methods of representation, among which the Aluminum Association of the United States (AA) and the ASTM (American of Testing Meterials) grades, especially AA grades, are more common. Its mark is given in the table below: AA grade alloy series AA grade alloy series 1××× Pure Aluminum (≥99.00%) 5×× Al-Mg Alloy 2××× Al-Cu Alloy 6××× Al-Mg-Si Alloy 3××× Al-Mn alloy 7×× Al-Zn alloy 4×××Al—Si alloy 8××× other alloys For example, Al-Cu alloy 2024, equivalent to our country's LY12; Al-Zn alloy 7075, is equivalent to our country's LC4. The material processing and heat treatment status codes, such as 6061-T 62 ; 5083-H 343 and so on, are also attached after the award. It is expressed as follows: F—original processing state. In the case of deformed alloys, it is a relatively initial state that does not require strict mechanical properties, such as hot rolling and extrusion. O-annealing in the recrystallized state, a softer state of the deformed alloy. In the naturally aged state after the W-solution treatment, the performance of the product changes with the time of the effect and is therefore unstable. H—cold hardening state. T - aging after solution treatment. The number in front of the T character indicates the basic type of heat treatment (from 1 to 10), and the digits after it indicate that the heat treatment details have changed. T1—Cools from the forming temperature and naturally ages to a substantially steady state. T2—annealed state (for castings only). T3 - natural aging after solution treatment. T31—Solid solution treatment after cold working (1%). T36—Solid solution treatment after cold working (6%). T37—Solution treatment Cold working (7%) after natural aging for 2219 alloy. T4 - natural aging after solution treatment. T41—Solvent water quenched after solution treatment. T411—Air cooled to room temperature after solution treatment, hardness between O and T6, low residual stress. T42—Natural aging after solution treatment. It is processed by the user and is suitable for 2024 alloy, which is slightly lower than T4. T5—Artificial aging after cooling from the molding temperature. T6 - artificial aging after solution treatment. T61-T41 + artificial aging. T611-Solution treatment, boiling water quenching. T62 - artificial aging after solution treatment. T7 - Stabilized after solution treatment. Improve dimensional stability, reduce residual stress and improve corrosion resistance. T72—Overaged after solution treatment. After T73-solid solution treatment, the aging time is lower than that of T6, and the corrosion resistance is significantly improved. T76-stage aging after solution treatment. T8 - solution treatment artificial aging after cold working. T81-cold work after solution treatment, artificial aging. To improve the deformation after solution treatment and improve strength. T86—cold working after solution treatment (6%), artificial aging. T87-T37+ artificial aging. T9 - artificial aging after solution treatment and then cold work. T10—cooled from the forming temperature and artificially aged after the aging. Tx51—Tensile treatment to eliminate residual stress after solution treatment. Longer deformation of the plate 0.5 to 3%, longer deformation of 1 to 3% of bars and profiles. X stands for 3, 4, 6, or 8, for example T351, T451, T651, T851. It is suitable for plates, draw bars, and wire rods. Tensile stress is eliminated without any correction and aging. T3510, T4510, and T8510 are applicable to extruded profiles. After stress relief is applied, the flatness is corrected to meet the tolerance, and the aging is applied. Tx52—In order to eliminate the residual stress after solution treatment, compressive deformation is performed. After solution treatment, 2.5% plastic deformation is performed and then aging, such as T352, T652. Tx53 - Eliminate thermal stress. Tx54—Compressive deformation to eliminate the residual stress after solution treatment of precision forgings.