Investigation of the Microstructure and Mechanical Properties of Quenching AZ31B in GO Nano-fluid

Automotive, modern aircraft fuselages, mobile phones, and laptop casings use AZ31B magnesium alloy. At room temperature, it is strong, flexible, corrosion-resistant, and weldable. Studies show that AZ31B's composition is insufficient for energy absorption, causing fracture. Because of the Hexagonal Close-Packed (HCP) structure's low mechanical strength and ductility. This study will examine how graphene oxide (GO) as a nano fluid quenching medium affects AZ31B's mechanical properties. After 3-hour heat treatment at 250 °C and 350 °C, the AZ31B is immersed for 30 minutes in five fluid media: air, distilled water, distilled water mixed with 0.1, 0.3, and 0.5 wt % Graphene Oxide to test the effect of nano fluid media on AZ31B strength. The scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX) were used to analyse the magnesium alloy AZ31B surface and the quenching medium's GO content. The surface roughness (Ra) of AZ31B magnesium alloy after heat treatment and quenching was also analysed. In addition, a dog-bone-shaped sample was used to determine AZ31B's ultimate tensile strength (UTS), yield strength, and young modulus after heat treatment and quenching for mechanical properties study. The analysis revealed that specimens heated to 350 ℃ had a smooth surface and a low (Ra) value of 1.869 to 1.964 µm. Additionally, the specimens exhibited higher UTS, Yield Strength, and Young modulus values than the control sample and specimens heated to 250℃. The analysis also showed that specimens with different wt % of GO in quenching media have a smooth surface and high mechanical properties like UTS of 250.305 MPa, yield strength of 130.086 MPa, and young modulus of 5608.85 MPa due to high concentrations of carbon and oxygen. The study found that heat treatment at 350℃ and quenching in distilled water + 0.3 wt % GO medium resulted in the best smooth surface and mechanical performance for AZ31B alloy.