Effects of ultrasonic vibration on performance and microstructure of AZ31 magnesium alloy under tensile deformation

• Published in: Journal of Central South University Vol. 25; no. 7; pp. 1545 - 1559
• Main Authors: Xie, Zhen-dong, Guan, Yan-jin, Yu, Xiao-hui, Zhu, Li-hua, Lin, Jun
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.07.2018; Springer Nature B.V
• Subjects: Amplitudes; Case hardenability; Deformation effects; Engineering; Forming; Hardening; Machine tool industry; Magnesium; Magnesium base alloys; Metal forming; Metallic Materials; Microhardness; Microstructure; Plastic deformation; Softening; Stress-strain relationships; Surface properties; Tensile deformation; Tensile tests; True stress; Twinning; Ultrasonic vibration; Vibration analysis; 拉伸实验; AZ31 镁合金; tensile test; microstructure; AZ31 magnesium alloy; plastic behavior; 微观组织; 超声振动; 塑性行为; ultrasonic vibration
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-018-3847-z

Ultrasonic vibration can reduce the forming force, decrease the friction in the metal forming process and improve the surface quality of the workpiece effectively. Tensile tests of AZ31 magnesium alloy were carried out. The stress–strain relationship, fracture modes of tensile specimens, microstructure and microhardness under different vibration conditions were analyzed, in order to study the effects of the ultrasonic vibration on microstructure and performance of AZ31 magnesium alloy under tensile deformation. The results showed that the different reductions of the true stress appeared under various ultrasonic vibration conditions, and the maximum decreasing range was 4.76%. The maximum microhardness difference among the 3 nodes selected along the specimen was HV 10.9. The fracture modes, plasticity and microstructure of AZ31 magnesium alloy also were affected by amplitude and action time of the ultrasonic vibration. The softening effect and the hardening effect occurred simultaneously when the ultrasonic vibration was applied. When the ultrasonic amplitude was 4.6 μm with short action time, the plastic deformation was dominated by twins and the softening effect was dominant. However, the twinning could be inhibited and the hardening effect became dominant in the case of high ultrasonic energy.