中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 1 January 2025 |
（1. Key Laboratory of Advanced Forging & Stamping Technology and Science, Ministry of Education, Yanshan University, Qinhuangdao 066004, China;
2. State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, Changsha 410083, China;
3. College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China;
4. Hebei Engineering Technology Research Center of Metal Precision Plastic Processing, Yanshan University, Qinhuangdao 066004, China;
5. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China）
Abstract:To elucidate the mechanisms of regulating the microstructure uniformity in 7050 aluminum forgings through surface cumulative plastic deformation (SCPD), the microstructure under different solution treatments was investigated using metallographic observation (OM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The findings demonstrate that the most uniform microstructure in the forgings is achieved with a solution treatment at 470 °C for 30 min. The SCPD process generates a significant number of needle-shaped precipitates, resulting in a higher dislocation density and stored energy. Solution treatments alleviate the pinning effect of second-phase particles and facilitate static recrystallization (SRX) in forgings, leading to a reduction in grain size. Additionally, mechanical testing results demonstrate 7%-13% increase in tensile strength and more uniform elongation of the forgings in different directions.
Key words: microstructure homogeneity; surface cumulative plastic deformation (SCPD); static recrystallization (SRX); dislocation density
