中文摘要：

对2024-T351铝合金进行了深冷激光喷丸强化（CLP）处理。结果表明,CLP处理使得2024-T351铝合金的表层金属发生了有效的晶粒细化,严重塑性变形层的晶粒尺寸大多在10μm以下,材料内第二相分布更为均匀;CLP处理后试样的表面硬度、抗拉强度和屈服强度比未处理样品的分别提高了34.1%、21.6%和28.9%,材料的延伸率也略有提高,实现了强度和塑性的同步增强。拉伸断口形貌表明,2024-T351铝合金经CLP处理后的断裂形式为韧性断裂,这有利于改善铝合金的拉伸性能。

英文摘要：

The cryogenic laser peening （CLP） of 20Z4-T351 aluminum alloys is performed. The results show that the effective grain refinement on the surface of 2024-T351 aluminum alloys is induced by the CLP, the grain size in the severe plastic deformation layer is mostly smaller than 10 μm, and the second-phase distribution is more homogeneous. Compared with those of untreated samples, the surface hardness, the tensile strength and the yield strength of samples treated by the CLP increase by 34.1%, 21.6 % and 28.9 %, respectively, and the elongation of materials increases slightly. The simultaneous improvement of strength and ductility is realized. The tensile fracture morphology indicates that the fracture form of 2024-T351 aluminum alloys strengthened by the CLP is a ductile fracture which is beneficial to improve the tensile property of aluminum alloys.