Microstructure evolution and mechanical properties of AZ31 magnesium alloy fabricated by high strain rate triaxial-forging

作者：Wu Yuan Zhi; Yan Hong Ge^*; Chen Ji Hua; Zhu Su Qin; Bo Hong Wei; Wang Lin Wei

来源：Chinese Journal of Nonferrous Metals, 2012, 22(11): 3000-3005.

• Accumulated strain
• Average grain size
• AZ31 alloy
• AZ31 magnesium alloy
• Different mechanisms
• High strain rate deformation
• High strain rates
• Homogeneous structure
• Microstructure and mechanical properties
• Microstructure evolutions
• Pneumatic power
• Ultimate tensile strength
• Wrought alloys

High strain rate triaxial-forging (HSRTF) of AZ31 magnesium alloy was conducted by the pneumatic power hammer at 350°C with a pass strain of 0.22, and the microstructure and mechanical properties of wrought alloy with the different accumulated strains was studied. The results show that the microstructure evolution is divided into two stages according to the different mechanisms: twin DRX (Dynamic recrystallization) induced grain refinement with the accumulated strain ∑ΔΕ lower than 1.32 and thermal activated grain growth with the accumulated strain ∑ΔΕ higher than 1.32. HSRTF is an efficient technique for the preparation of the fine-grained AZ31 alloys with perfect mechanical properties ascribe to the auxo-action of twins on DRX during high strain rate deformation. And a homogeneous structure with the average grain size of 7.4μm can be obtained with the accumulated strain ∑ΔΕ of 1.32, which has the ultimate tensile strength (UTS), yield strength (YS) and elongation of 313 MPa, 209 MPa and 28.6%, respectively.

• 出版日期2012