Effects of ultrasonic vibration on plastic deformation of AZ31 during the tensile process

Abstract

An investigation on the plastic behavior of AZ31 magnesium alloy under ultrasonic vibration (with a frequency of 15 kHz and a maximum output of 2 kW) during the process of tension at room temperature was conducted to reveal the volume effect of the vibrated plastic deformation of AZ31. The characteristics of mechanical properties and microstructures of AZ31 under routine and vibrated tensile processes with different amplitudes were compared. It is found that ultrasonic vibration has a remarkable influence on the plastic behavior of AZ31 which can be summarized into two opposite aspects: the softening effect which reduces the flow resistance and improves the plasticity, and the hardening effect which decreases the formability. When a lower amplitude or vibration energy is applied to the tensile sample, the softening effect dominates, leading to a decrease of AZ31 deformation resistance with an increase of formability. Under the application of a high-vibrating amplitude, the hardening effect dominates, resulting in the decline of plasticity and brittle fracture of the samples.

Keywords

ultrasonic effects / tensile testing / magnesium alloys / plastic deformation

References

[1] Huang G.S., Huang G.J., Wang L.Y., et al. Ductility enhancement of wrought magnesium alloys. Mater. Rev., 2006, 20(1): 39.

[2] Yu K., Li W.X., Wang R.C. Plastic deformation mechanism of magnesium alloys. Chin. J. Nonferrous Met., 2005, 15(7): 1081.

[3] Blaha F., Langenecker B. Elongation of zinc monocrystals under ultrasonic action. Die Naturwiss., 1955, 42, 556.

[4] Langenecker B. Effect of ultrasound on deformation characteristics of metals. IEEE Trans. Sonics Ultrason., 1966, 1, 1.

[5] D.R. Culp and H.T. Gencsoy, Metal deformation with ultrasound, Ultrason. Symp., 1973, p.195.

[6] Hung J.C., Tsai Y.C., Hung C. Frictional effect of ultrasonic-vibration on upsetting. Ultrasonics, 2007, 46, 277.

[7] Daud Y., Lucas M., Huang Z.H. Modelling the effects of superimposed ultrasonic vibrations on tension and compression tests of aluminum. J. Mater. Process. Technol., 2007, 186, 179.

[8] Hayashi M., Jin M., Thipprakmas S., et al. Simulation of ultrasonic-vibration drawing using the finite element method (FEM). J. Mater. Process. Technol., 2003, 140, 30.

[9] Wen T., Pei C.L., Li C.K. Application of vibration in plastic forming processes. Hot Work. Technol., 2009, 38, 114.

[10] Zheng J.X., Hu H., Cheng J. The development of constitutive equations of solid materials under the action of super frequency vibration. J. Harbin Inst. Technol., 1997, 29(1): 6.

[11] Bozdana A.T., Gindy N.N.Z., Li H. Deep cold rolling with ultrasonic vibrations—a new mechanical surface enhancement technique. Int. J. Mach. Tools Manuf., 2005, 45, 713.

[12] Jimma T., Kasuga Y., Iwaki N., et al. An application of ultrasonic vibration to the deep drawing process. J. Mater. Process. Techonl., 1998, 80–81, 406.

[13] Siegert K., Mock A. Wire drawing with ultrasonically oscillating dies. J. Mater. Process. Technol., 1996, 60, 657.

[14] Ashida Y., Aoyama H. Press forming using ultrasonic vibration. J. Mater. Process. Techonl., 2007, 187–188, 118.

[15] Zhang Y.D. Ultrasonic Machining and its Application, 1995 Beijing, National Defense Industry Press, 17.