Effect of Pb on Microstructure and Mechanical Properties of AZ91 Magnesium Alloy

Document Type : Research Paper

Authors

• Mohammad Reza Askaran ¹
• Masoud Emamy ²
• Mehdi Malekan ³

¹ MSc student, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran

² School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran

³ School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 14395-515, Tehran, Iran

Abstract

In this study, the effect of different amounts of Pb (0, 0.5, 1, 3 wt.%) was investigated on the microstructure and mechanical properties of the AZ91 magnesium alloy. The microstructure and mechanical properties were Studied using optical microscope, scanning electron microscope (SEM), X-ray diffractometer (XRD) and tensile test. The results showed that by adding Pb, the volume fraction of the β- Mg17Al12 phase decreased. It was also found that the grain size by 1 wt.% Pb addition decreased significantly and the formation tendency of the divorced eutectic phase reduced. Furthermore, the optimum amount of UTS and elongation were observed by the addition of 1 wt.% Pb to AZ91 magnesium alloy. UTS and elongation increased from 129 MPa and 2.7% to 160 MPa and 7%, respectively, when the 1 wt.% Pb was added to the AZ91 alloy. The fracture surface observations showed that the fracture mode in these alloys were cleavage and the Pb addition does not change the fracture mode.

Keywords

• AZ91 magnesium alloy
• Lead (Pb)
• Microstructure
• mechanical properties
• Grain size

20.1001.1.22285946.1397.9.33.3.7

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AZ 36 بررسی تاثیر سرب بر ریز ساختار و خواص مکانیکی آلیاژ منیزیم 91