Nanocomposite Fe-Al Intermetallic Coating Obtained by Gas Detonation Spraying of Milled Self-Decomposing Powder

Abstract

The nanocomposite structure of Fe-Al intermetallic coating, created in situ during gas detonation spraying (GDS) of as-milled self-decomposing powder and containing disordered 8 nm FeAl nanocrystals, was analyzed using scanning electron microscopy (SEM) with energy-dispersive x-ray (EDX) spectroscopy, transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and x-ray diffraction methods. It is found that the Fe-Al coating is characterized by a sublayer morphology consisting of flattened and partially melted splats containing a wide Al range from about 26 to 52 at.%, as well as Al 2 O 3 oxides, created in situ at the internal interfaces of splats during the GDS process. The complex oxide films, identified as amorphous Al 2 O 3 , which are formed in the nanocrystalline Fe-Al matrix of the GDS coating behave like a composite reinforcement in the intermetallic Fe-Al coating. The combined presence of nanosized subgrains in the Fe-Al matrix and the Al 2 O 3 nanoceramic dispersoids significantly increases the microhardness of the coating.

The Effect of Nanometric α-Al2O3 Addition on Structure and Mechanical Properties of Feal Alloys Fabricated by Lens Technique

“…a mechanical vibration, an electromagnetic induction). An addition of nanoand micron-sized particles is a new method for an improvement of mechanical properties of metals and alloys through their microstructure modification [1,[3][4][5]. One of the most important required feature of these modifiers is their good chemical and thermal stability (originating from a high melting temperature).…”

“…[5,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]37]. However, these methods are complex, inefficient, energy-consuming and generates high production costs.…”

Multi-axial forging of Fe3Al-base intermetallic alloy and its mechanical properties

“…Particularly noteworthy are the intermetallic Fe 3 Albased alloys that could potentially substitute for more expensive superalloys and creep-resistant steels. They are characterized by a combination of interesting functional characteristics such as an excellent resistance to oxidation, sulfidation and carburizing, good resistance to corrosion in sea water, high resistance to wear, erosion, or cavitation, and high strength to weight ratio [2][3][4][5][6]. The Fe 3 Al phase, depending on the chemical composition and temperature has either a D0 3 or B2 ordered structure, which is derivative of the body-centered cubic BCC or A2 structure.…”

Wire Electrical Discharge Machining Of Feal Intermetallic Sinters Without And With Addition Of Nano-Al2O3 Oxide Ceramic

“…These materials can be produced by a conventional melting and casting, but finally obtained coarse-grained structure required further multivariant thermo-mechanical treatment [11][12][13][14]. Nowadays, Fe-Al intermetallics are usually used as a protective coatings deposited by a detonation gas spraying [15][16][17][18][19][20][21][22][23][24] and a laser cladding [25][26][27][28]) or as reactive, exothermic mixtures (consisted of Fe and Al elemental powder) for joining other materials (e.g. in the form of thin foils) [29].…”