Influence of Plastic Deformation on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

Abstract:

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperature (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure changes of AZ80 magnesium alloy have been investigated through tensile test and via ZEISS digital metallographic microscope observation. Research indicates that the alloy’s plasticity gradually decreases as the temperature increases, and that the alloy’s tensile strength varies with the extrusion ratio. At 330°C, the alloy’s particle grain is small and a small amount of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390 Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, both the tensile strength and plasticity increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.

• Periodical: Advanced Materials Research (Volumes 291-294)
• Pages: 1082-1086
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.291-294.1082
• Online since: July 2011
• Authors: Yao Jin Wu, Zhi Ming Zhang, Bao Cheng Li, Bao Hong Zhang, Jian Min Yu, Yong Xue
• Keywords: AZ80 Magnesium Alloy, Microstructure, Plastic Deformation

References

[1] ZHOU Haitao, MA Chunjiang, ZENG Xiaoqin, DING Wenjiang: Materials Review,17-11 (2003), pp.16-18

[2] T. Homma, N. Kunito: Scripta Materialia, 61 (2009), pp.644-647

[3] CHEN Zhenhua, XU Fangyan, FU Dingfa, XIA Weijun: Chemical Industry and Engineering Progress, 25-2 (2006), pp.140-146

[4] LIU Chuming: The Chinese Journal of Nonferrous Metals, 16-1 (2006), pp.1-12

[5] ZHANG Jumei, Jiang Bailing, Wang Zhihu, Xia Pengju, Ge Kaichen: Special Casting & Nonferrous alloys, 1 (2008), pp.60-62

[6] A. Yakubtsov, B. J. Diaka: Materials Science and Engineering A, 496 (2008), pp.247-255

[7] GUO Qiang, YAN Hong-ge, CHEN Zhen-hua, ZHANG Hui: Journal of Plasticity Engineering, 7 (2006), pp.739-744

[8] P. Zhang, J. Lindemann: Scripta Materialia, 52 (2005), pp.485-490

[9] Y. Uematsu, K. Tokaji, M. Kamakura, K. Uchida: Materials Science and Engineering, 434 (2006), pp.131-140

[10] Muhammad Shahzad, Lothar Wagner: Materials Science and Engineering A, 506 (2009), pp.141-147