Scanning Electro-Microscopy (SEM) of light magnesium alloy AZ31B on strain rate effect

• Main Author: Muhammad Syamil Shamsuri.
• Other Authors: Shu Dong Wei
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering; DRNTU::Engineering::Materials::Metallic materials::Alloys
• Online Access: http://hdl.handle.net/10356/53257
• Institution: Nanyang Technological University

Today in the modern world, lightweight materials are more widely used for various types of applications. From designing of mobile phone to automobile and protective materials, the demand for lightweight materials in the modern world is ever increasing. There has been increasing pressure forthe government and commercial companies to impose on a lighter material for its automotive and aerospace applications to save fuel usage and have a positive effect on the environment. Materials such as aluminium, zinc and magnesium alloys are more commonly used due to their high strength to weight ratio as compared to steel which have generally better mechanical properties but higher density. In this project, the strain rate effect on the microstructure of magnesium alloy AZ31B under compression is being analysed. The alloy is subjected to 5 different strain rates of 10-4/s, 300/s, 500/s, 1500/s and 3000/s. Preparation of the samples are first carried out by using the methods of Cutting, Mounting, Grinding, Polishing and Etching, all done in sequence. The microstructures of the samples are then analysed by first using the Optical Microscope (OM) to obtain 5X, 10X and 20X zoom, and subsequently by using the Scanning Electro-Microscope (SEM). The material composition is also identified by using Energy-Dispersive X-Ray Spectroscopy (EDX). These images and data are then compared for the effect of the various strain rates of AZ31B magnesium alloy. The main deformation mechanism for the various strain rates observed was slip and mechanical twinning. These deformation mechanisms observed in the microstructure promoted plastic deformation of the magnesium alloy and were the main factors of the decrease of its mechanical properties such as ductility and increase in its hardness value and compressive strength.