Finite element analysis and experiment on viscous warm pressure bulging of AZ31B magnesium alloy

Abstract

Aiming at overcoming the low plasticity of magnesium alloy at room temperature, we researched viscous warm pressure bulging(VWPB) of AZ31B magnesium alloy based on the excellent thermal stability of viscous medium under the warm forming condition. The potential improvements of plastic deformation ability and forming quality of AZ31B magnesium alloy are expected with the aid of thermal characteristics of viscous medium. During bulging process the velocity field variation and pressure stress field distribution of viscous medium are observed at different temperatures through which the effect of temperature on the mechanical property of viscous medium and AZ31B magnesium alloy are analyzed. The results show that the formability of AZ31B magnesium alloy increases first and then decreases as the temperature increases and it is the best at 200 °C. On the other hand, the viscous medium which can build non-uniform pressure stress field also exhibits a good flow property at elevated temperature, and it is helpful to improving the formability of AZ31B magnesium alloy.

Keywords

viscous warm pressure bulging / AZ31B magnesium alloy / formability / flow property

References

[1] Guo Y, Zhang M, Jin Yaxu. Refinement Mechanism of Insitu Al4C3 Particles on AZ91 Magnesium Alloys[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed, 2014, 29(1): 154-158.

[2] Liu Qing. Research Progress on Plastic Deformation Mechanism of Mg Alloys[J]. Acta Metallurgica Sinica, 2010, 46(11): 1458-1472.

[3] Liu Y, Li W, Li Yuanyuan. The Stamping Formability of AZ31 Magnesium Alloy Sheet Improved by Equal-Channel Angular Pressing[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2010, 25(2): 234-237.

[4] Palaniswamy H, Ngaile G, Altan T. Finite Element Simulation of Magnesium Alloy Sheet Forming at Elevated Temperatures[J]. Journal of Materials Processing Technology, 2004, 146(1): 52

[5] Mustafa Kemal Kulekei. Magnesium and Its Alloys Applications in Automotive Industry[J]. The International Journal of Advanced Manufacturing Technology, 2008, 39(9–10): 851-865.

[6] Koh Y, Kim D, Seok D-Y, et al. Characterization of Mechanical Property of Magnesium AZ31 Alloy Sheets for Warm Temperature Forming[J]. International Journal of Mechanical Sciences, 2015, 93: 204-217.

[7] Zhang S, Song G, Song H, et al. Deformation Mechanism and Warm Forming Technology for Magnesium Alloys Sheets[J]. Journal of Mechanical Engineering, 2012, 48(18): 28-34.

[8] Maksoud IA, Ahmed H, Rödel J. Investigation of the Effect of Strain Rate and Temperature on the Deformability and Microstructure Evolution of AZ31 Magnesium Alloy[J]. Materials Science and Engineering, 2009, 504(1): 40-48.

[9] Ghaffari Tari D, Worswick MJ. Elevated Temperature Constitutive Behavior and Simulation of Warm Forming of AZ31B[J]. Journal of Materials Processing Technology, 2015, 221: 40-55.

[10] Wang W, Huang L, Tao K, et al. Formability and Numerical Simulation of AZ31B Magnesium Alloy Sheet in Warm Stamping Process[J]. Materials and Design, 2015, 87: 835-844.

[11] Mahabunphachai S, Koc M. Material Behavior and Formability of Magnesium AZ31 Sheet Alloy under Warm Hydroforming Conditions[J]. Center for Precision Forming, 2009, 34: 105-109.

[12] Liu J, Wang Z, Li Y, et al. Research on Viscous Pressure Forming of Aluminum Alloy Sheet Conical Part at Warm Temperature[J]. Forging and Stamping Technology, 2007, 32(5): 33-36.

[13] Gao T, Liu Y, Chen P, et al. Analysis of Bulging Process of Aluminum Alloy by Overlapping Sheet Metal and Its Formability[J]. Transactions of Nonferrous Metals Society of China, 2015, 25(4): 1050-1055.

[14] Wang Z, Liu Jianguang. Sectional Finite Element Analysis of Coupled Deformation Between Elastoplastic Sheet Metal and Visco- Elastoplastic Body[J]. ACTA Mechanica Solida Sinica, 2011, 24(2): 153-164.

[15] Gao T, Liu Y, Wang Zhongjin. Viscous Inner and Outer Ppressure Forming Method of Thin-Walled Tube and Its Application[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2015, 20(2): 404-407.

[16] Liu J, Wang Zhongjin. Prediction of Wrinkling and Fracturing in Viscous Pressure Forming (VPF) by Using the Coupled Deformation Sectional Finite Element Method[J]. Computational Materials Science, 2010, 48(2): 381-389.