FABRICATION OF HIGH STRENGTH MAGNESIUM ALLOY WITHOUT RARE EARTH ELEMENTS

• Main Author: Rahmaniyah, Primawati
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43764
• Institution: Institut Teknologi Bandung

Magnesium has the lowest density among other types of metall but Mg also has low strength. Therefore various studies have been carried out to increase the strength of magnesium alloy by adding various alloying elements. Rare earth metals are the most common type of alloying elements for magnesium alloy because its effectivity for increasing the strength of magnesium alloy, but rare earth is expensive. Based on the literature studies about high strength magnesium alloy, the addition of Zn, Al, Cu, and Mn alloys produced high strength magnesium alloys with cheaper price. The fabrication of magnesium alloy is carried out by a casting process followed by a heat treatment process (solution treatment and two step aging). The casting process is carried out in the atmospheric conditions by adding protective gasses CO2 and HFC-134a. the comparison between the as-cast alloy and heat treated alloy will be discussed. The charactirisations are Vickers Hardness Test, Tensile Test, X-ray Fluorescence Spectroscopy (XRF) to examine the chemical composition of the alloy, Light Optical Microscopy (LOM) and Scanning Electron Microscopy (SEM) to observe the microstructure, Electron Dispersion Spectroscopy (EDS) and X-ray Diffraction (XRD) to examine the compounds that formed in the alloy. An alloy with the maximum composition of Mg-5.2Zn-0.59Al-0.29Cu-0.55Mn alloy was produced after 2 casting trial. The results showed that Magnesium alloy consist of ?-Mg, MgZn, and MgZnCu phases. After solution treatment and two step aging, magnesium alloy reached maximum value of UTS 264,26 MPa with elongation of 2,81% and the maximum hardness 99,18 HV. So the high strength magnesium alloy can be obtained by the addition of alloying elements Zn, Al, Cu, Mn.