1 National Engineering Research Center for Plastic Working of Aluminum Alloys, Shandong Nanshan Aluminum Co., Ltd., Longkou 265713, China 2 Shandong Nanshan Science and Technology Research Institute Co., Ltd., Longkou 265713,China 3 College of Engineering, Yantai Nanshan University, Longkou 265713,China
Abstract: In order to investigate the relationship between element diffusion and performance of 2024 alclad sheet for the large aircraft skin. In this work, OM, SEM, and tensile tests are used to study the effects of solution time on the transition layer element diffusion and the mechanical properties of 2024 alu minum alloy clad sheet. The results show that the main alloy elements of the transition layer begin to gradually expand to the alu minum clad layer with the solution time increasing. When the solution time is 10 min, the diffusion of the main alloy elements Mg and Cu is very obvious. When the solution time reaches to 40 min, the main alloy elements almost diffused to the entire coating layer. The mechanical properties first increase rapidly with the solid solution time increasing, then tends to increase slower. The yield strength of the sample after solution treatment was 137 MPa for 2 min, and reached 272 MPa after 10 min. With the increase of solution time, the yield strength increased slowly, and basically remained at 280 MPa after 15 min. Therefore, when the continuous annealing line is used to solution treatment of large-size 2024 alclad sheet, the appropriate solution time is 10 min. The diffusion distance of alloy elements is small, and the yield strength of the alloy also meets the requirements after this solution treatment process.