A strong and deformable in-situ magnesium nanocomposite igniting above 1000 °C

Abstract

Magnesium has been trending of late in automobile, aerospace, defense, sports, electronic and biomedical sectors as it offers an advantage in light-weighting. In aluminum, titanium, and steel dominated aerospace and defense sectors, applications of Mg were banned/restricted until recently due to perceived easy ignition and inability to self-extinguish immediately. Strength is generally inversely related to ductility, weak texture and unrelated to ignition resistance, making it challenging to optimize all four concurrently in a material. We address this challenge by designing a low density (~1.76 g.cm−3) in-situ Mg nanocomposite. It is a resultant of a sequence of in-situ reactions during melt processing and extrusion. The in-situ formed Y2O3 nanoparticles exhibit coherency with matrix and lead to development of large amount of elastic and plastic strain fields around them. These nanoparticles and secondary phases (Mg2Ca and Mg2Y) are responsible for the nanocomposite’s high tensile strength (~343 MPa). A weak texture mediated tensile ductility of 30% and compressive failure strain of 44% is observed. Further, the ignition temperature increased to 1045 °C (near the boiling point of Mg) due to the formation of protective surficial oxide layers aided by the presence of insulating Y2O3 nanoparticles, rendering the nanocomposite outperform other traditional commercial Mg-based materials.

Fe3O4 Nanoparticle-Reinforced Magnesium Nanocomposites Processed via Disintegrated Melt Deposition and Turning-Induced Deformation Techniques

“…A 2% addition of Fe 3 O 4 can help in raising the ignition temperature by 45 • C. Although, the same trend of increase in ignition temperature with addition of Fe 3 O 4 is observed in the materials processed by TID, the relative ignition temperatures values show a slight drop in ignition temperatures compared to their counterparts processed by DMD. The nanocomposites used have already displayed a marked improvement in ignition temperature when compared to pure Mg which auto-ignites at 473 • C [36] and ignites in air under a constant heating rate of 590 • C. This is likely caused by the presence of the Fe 3 O 4 nanoparticles which are thermally stable and provide insulating effects to the Mg matrix surfaces by hindering heat transfer at some points, much like other oxides such as Y 2 O 3 , as has been explored previously [37]. This results in elevating the ignition temperatures as Fe 3 O 4 content increases.…”

Enhancing Properties of Aerospace Alloy Elektron 21 Using Boron Carbide Nanoparticles as Reinforcement

“…To extend their applications to other aircraft components apart from seat frames, such as gearbox housing casings, etc., improvement of strength and high temperature properties such as ignition resistance is crucial [10]. Addition of ceramic and metallic particulates as reinforcements is one of the methods to improve magnesium's property profile and performance, especially high temperature properties due to their thermal stabilities [11,12]. B 4 C nanoparticles were demonstrated to be promising as reinforcements owing to their role in improving the strengths of magnesium [13].…”

Introductory Chapter: An Insight into Fascinating Potential of Magnesium

“…Hence, they are predominantly being used in the automobile sector as sheets or even engine blocks and other automobile components such as in steering wheels, boot area, etc. Further, for robust and elevated temperature applications such as engine blocks, newly developed highstrength magnesium alloys and alloy nanocomposites can be used as they demonstrate good thermal and dimensional stabilities [7][8][9][10][11].…”

“…Ever since upliftment of the ban on magnesium by FAA [13], there is an ever-increasing demand for highperformance magnesium alloys for reducing weight in aircraft structures such as interior components, fuselage structures, gearboxes, aero engine frames, helicopter transmissions, covers and components, flight control systems, electronic housings, and aircraft wheels [14]. With advancement in the alloy design and material development, for the abovementioned as well as other applications in both commercial and military aircrafts, advanced higher-performance magnesium alloys and composites that are also ignition-resistant or ignition proof and corrosion-resistant suit the requirement of the aviation industries and can help in achieving sustainability and protecting the environment [8,[15][16][17].…”