AZ31-MWCNT Composites Fabricated Through Powder Metallurgy for Aerospace Applications

Abstract

<div class="section abstract"><div class="htmlview paragraph">The aerospace industry's unceasing quest for lightweight materials with exceptional mechanical properties has led to groundbreaking advancements in material technology. Historically, aluminum alloys and their composites have held the throne in aerospace applications owing to their remarkable strength-to-weight ratio. However, recent developments have catapulted magnesium and its alloys into the spotlight. Magnesium possesses two-thirds of aluminum's density, making it a tantalizing option for applications with regard to weight-sensitive aerospace components. To further enhance magnesium's mechanical properties, researchers have delved into the realm of metal matrix composites (MMCs), using reinforcements such as Alumina, Silicon carbide, Boron carbide and Titanium carbide. However, meager information is available as regards to use of Multi-Walled Carbon Nanotubes (MWCNTs) as a reinforcement in magnesium based MMCs although, CNTs exhibit excellent stiffness coupled with very low density.</div><div class="htmlview paragraph">In the light of above, the present work focusses on development of lightweight magnesium based MMCs using CNTs as nano-fillers. This research explores the synthesis and characterization of MWCNT-reinforced AZ31 magnesium alloy composites. The weight fractions of MWCNTs were varied from 0.3% to 1.2% in steps of 0.3%. Powder metallurgy technique has been used to develop the composite. Ball milling was used to blend the composite mixture of AZ31 & CNTs. Microstructural studies such as optical micrograph, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been carried out on the developed composites. Micro hardness and compression strength tests have been carried out on the developed composite. X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) studies have also been carried out to analyze the compositional elements present in the developed composite. Microstructural studies reveal a fairly uniform distribution of CNTs within the matrix alloy AZ31. A significant improvement in both hardness and compressive strength have been observed for the developed composites when compared with the base alloy.</div></div>