EFFECT OF SCANDIUM ADDITION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ALUMINUM ALLOY 7075

• Main Author: Dennis, Bryan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71705
• Institution: Institut Teknologi Bandung

Aluminium is one of the most widely used metals because of its high specific strength. The aluminium 7XXX series with zinc as the main alloy is widely used in the aerospace industry, for example bearing components in aircraft, because of its superiority, which is heat-treatable with high yield strength. One of the processes for strengthening aluminium is through a grain refinement process with the addition of grain refiners, one of which is scandium. This study was designed to determine the effect of scandium on microstructure and mechanical strength. The process begins with alloy casting and homogenization. Metallography was carried out to see the microstructure and mechanical testing of tensile and hardness tests to determine its strength. Characterization that conducted in this thesis are DSC, SEM-EDS, and XRD. The addition of 0.25 wt% and 0.50 wt% scandium in the as-cast condition reduced the grain size by 30% and 38%, while in the as-homogenized condition, the reduction was 45% and 67%. The tensile strength of as-cast with the addition of 0.25 wt% of scandium increased by 77.08%, and by the addition of 0.50wt% by 47%. The hardness of aluminium alloy 7075 increased with the addition of scandium in the as-cast by 12% for both variations of scandium addition and in as-homogenized conditions by 2% and 7% at the addition of 0.25 wt% and 0.50 wt%.