THE EFFECT OF AGING TIME ON CORROSION RESISTANCE OF MG-4WT%Y ALLOYS

• Main Author: Perenius Sitanggang, Ryanto
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/39604
• Institution: Institut Teknologi Bandung

Pure magnesium (Mg) has excellent biocompatibility in the human body, on the other hand stiffness of magnesium that approaches stiffness of human cortical bone can minimize stress shielding phenomena. However, the relatively high rate of degradation and evolution of hydrogen becomes a weakness of pure magnesium. So that appropriate alloy designation and treatment are needed to improve these weaknesses. Yttrium (Y) as a rare earth element has been widely studied as a magnesium alloy element due to increased hardness, corrosion resistance and good biocompatibility. However, the existence of a second phase such as ?-Mg24Y5 which is more stable causes micro-galvanic corrosion with the ?-Mg matrix. This study aims to see the effect of aging at 200oC in the Mg-4wt.%Y specimen for 3, 6, 24, 48, 72, 96, and 120 hours. Corrosion testing with immersion simulation of body fluids with ASTM G31-72 standard for 72 hours testing. A significant reduction in corrosion rate was obtained. This is due to the barrier effect of the second phase which is interconnected. The existence of the second phase and its distribution can be seen in micro-vickers hardness, characterization of x-ray diffraction and electron microscopy with energy dispersive spectroscopy.