固溶时效对2524合金板材组织和性能的影响

Effects of Solid Solution and Aging Treatment on Microstructure and Mechanical Properties of 2524 Aluminum Alloy Sheet

采用金相显微镜(OM)、差热分析(DSC)、X射线衍射(XRD)、拉伸试验机等,研究了固溶时效处理对大应变轧制2524铝合金板材显微组织及力学性能的影响。研究表明,轧制态2524铝合金中轧制面组织呈纤维状且存在大量的Al_2Cu和Al_2CuMg相。合金在455～495℃之间,固溶处理温度越高,时间越长,粗大的第二相溶解越充分。2524铝合金经495℃×60min固溶处理后,析出相基本溶解,2524铝合金的抗拉强度,屈服强度和伸长率分别为412.6 MPa、350.7 MPa和17.9%,合金经505℃固溶处理后,出现过烧组织特征,力学性能降低。合金经时效处理后强化相均匀析出,合金性能得到强化。合金经190℃×6h时效处理后,2524铝合金的抗拉强度、屈服强度和伸长率分别为464.6MPa、395MPa和22%。

The microstructure and mechanical properties of large strain rolled 2524 aluminum alloy sheet were investigated by means of optical microscope（OM）,differential thermal analysis（DSC）,X-ray diffraction（XRD）,tensile testing machine.The results reveal that the microstructure of the rolled 2524 aluminum alloy presents fibrous with a large amount of Al2Cu and Al2CuMg phases.With solid solution treated at 455 ℃ to 495 ℃,the higher solid solution treatment temperature and the longer treatment time are,the more second phase dissolved.After solution treated at 495℃for 60 min,the precipitated phase is basically dissolved,where the tensile strength,yield strength and elongation of 2524 aluminum alloy reach up to 412.6 MPa,350.7 MPa and 17.9%,respectively.After solid solution treated at 505℃,over-burning structure appears and thus the mechanical properties are weakened.After aging treatment,the strengthening phase is uniformly precipitated and the alloy is strengthened.The tensile strength,yield strength and elongation of the 2524 aluminum alloy after aging at 190 ℃ for 6 hare 464.6 MPa,395 MPa and 22%,respectively.