Study of the Effect of Zirconium Addition on Cyclic Oxidation and Thermal Shock Resistance of Smelted Intermetallic NiAl

• Main Author: Cleave Bonar, Conrad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36904
• Institution: Institut Teknologi Bandung

Intermetallic NiAl compound has become a candidate material to be used in high temperature applications, due to its high temperature resistance. Intermetallic NiAl is a strong candidate because it is different in nature from its constituent material, in which it has a higher melting temperature, high thermal conductivity, and has the ability to form a passive layer. For high temperature applications, the oxidation properties of NiAl still need improvements. Addition of reactive elements such as zirconium is known to improve oxidation properties. The cyclic oxidation resistance of NiAl was further tested, along with its relationship with zirconium doping concentrations, i.e. without doping, 0.1 at%, 0.2 at%, and 0.3 at% doping zirconium. All NiAl specimens were made using electric arc furnace (EAF). The smelted results are tested using XRD to examine compounds and elements formed in them. Cycle oxidation is carried out, each cycle is one hour at a temperature of 1200 ?C, then cooled, followed by measurment of changes in mass in each cycle. It was found through cyclic oxidation that scale spalling had not occurred in all four samples after 40 cycles, and the addition of mass due to thickening of the oxide layer increased with increasing zirconium content. Thermal shock testing was carried out on each specimen by exposing it to a temperature of 1200 ?C, then rapid cooling with liquid nitrogen. It was found that the resistance to thermal shock of all four specimens was good.