中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 28 No. 1 January 2018 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 2. Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China; 3. Key Laboratory of Ministry of Education for Nonferrous Metal Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Effects of strain rate on the microstructure evolution and thermal stability of 1050 commercial pure aluminum processed by means of split Hopkinson pressure bar (SHPB) and Instron-3369 mechanical testing machine were investigated. Samples in the deformed state and after various annealing treatments at 423-523 K (150-250 °C) for 1 h were characterized by TEM and hardness test. The result reveals that the samples in the deformed state were mainly composed of elongated subgrains/cells with high density of dislocations. Microstructures of the quasi-static compressed aluminum were quite stable throughout the temperature range studied, and no significant grain growth was observed. However, for the dynamic impacted one, recrystallized grains with an average grain size of 4.7 μm were evolved after annealing at 523 K (250 °C) for 1 h. It is suggested that the annealing behavior of this dynamic deformed aluminum is a continuous process of grain coarsening, rather than the traditional discontinuous recrystallization for the quasi-static compressed aluminum.
Key words: strain rate; thermal stability; continuous recrystallization; 1050 commercial pure aluminum
