Evolution of Microstructure and Tensile Properties of 6061 Aluminum Alloy during Multi-directional Forging

The multi-directional forging process of 6061 aluminum alloy at initial forging temperatures of 250-350℃ was simulated by finite element simulation method, and the optimal multi-direction forging process was obtained and verified by microstructure observation and tensile property testing. The results show that the optimal initial forging temperature of the multi-directional forging process of 6061 aluminum alloy obtained by finite element simulation was 300℃. At the optimal initial forging temperature, complete dynamic recrystallization of 6061 aluminum alloy occurred after 4 cycles of multi-directional forging; the grains were highly refined and distributed uniformly; size of some grains was less than 1 μm and 6061 aluminum alloy had ultra-fine grains. The tensile properties of 6061 aluminum alloy were significantly improved. The tensile strength increased from 265.33 MPa before forging to 344.74 MPa, and the elongation after fracture decreased slightly.