Annealing Effects on Microstructure and Mechanical Properties of Ultrafine-Grained Al Composites Reinforced with Nano-Al2O3 by Rotary Swaging

作者：Chen, Cunguang^*; Wang, Wenwen; Guo, Zhimeng; Sun, Chunbao; Volinsky, Alex A.; Paley, Vladislav

来源：Journal of Materials Engineering and Performance, 2018, 27(4): 1738-1745.

DOI：10.1007/s11665-018-3301-2

• Al composite
• mechanical properties
• microstructure evolution
• powder metallurgy
• rotary swaging

Microstructure evolution and variations in mechanical properties of Al-Al2O3 nanocomposite produced by powder metallurgy were investigated and compared with commercially pure aluminum (Al-1050) after furnace annealing. Fine gas-atomized Al powder compacts were first sintered in flowing nitrogen, subsequently consolidated into wires by rotary swaging and eventually annealed at 300 and 500 A degrees C for 24 h each. Scanning and transmission electron microscopy with energy-dispersive spectroscopy was utilized to document the microstructure evolution. Rotary swaging was proven to lead to a marked decrease in grain size. After heavy swaging to true deformation degree of phi = 6 and annealing at 500 A degrees C, obvious recrystallization was observed at Al-1050's existing grain boundaries and the crystals began to grow perpendicular to the flow direction. In the Al-Al2O3 nanocomposite, fabricated from d (50) = 6 mu m Al powder, recrystallization partially occurred, while grains were still extremely fine. Due to the dual role of fine-grained Al2O3 dispersion strengthening, the nanocomposite showed improved mechanical performance in terms of tensile strength, approximately twice higher than Al-1050 after annealing at 500 A degrees C.

• 单位
  北京科技大学