The Effect of Oxygen Partial Pressure on Microstructure and Properties of Fe40Al Alloy Sintered under Vacuum

Abstract

This paper presents the results of studies on the influence of oxygen partial pressure (vacuum level in the chamber) on the properties of FeAl intermetallics. One of the problems in the application of classical methods of prepared Fe-Al intermetallic is the occurrence of oxides. Applying a vacuum during sintering should reduce this effect. In order to analyze the effect of oxygen partial pressure on sample properties, five samples were processed (by a pressure-assisted induction sintering—PAIS method) under the following pressures: 3, 8, 30, 80, and 300 mbar (corresponding to oxygen partial pressures of 0.63, 1.68, 6.3, 16.8, and 63 mbar, respectively). The chemical and phase composition, hardness, density, and microstructure observations indicate that applying a vacuum significantly impacts intermetallic samples. The compact sintered at pressure 3 mbar is characterized by the most homogeneous microstructure, the highest density, high hardness, and nearly homogeneous chemical composition.

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.…”

Unexpected High Ductility of Fe40Al Alloys at Room Temperature

“…Aluminium powder (AG 90/99.7) was supplied by Benda Lutz Company (Skawina, Poland). The exact characteristics of these powders were presented in previous works [21]. A mixture consisting of 60 atomic percent iron and 40 atomic percent aluminium was prepared.…”

“…Usually, the maximum deformation exhibited by these materials does not exceed a few percent [18,19]. For several years, we have been researching Fe40Al sinters obtained by pressure-assisted induction sintering (PAIS) [20][21][22][23]. Several hundred variants of sample manufacturing parameters were already made, and in all cases, sinters whose plastic properties were extremely different from those known from the literature were obtained.…”

Effect of Low Environmental Pressure on Sintering Behavior of NASICON-Type Li1.3Al0.3Ti1.7(PO4)3Solid Electrolytes: AnIn SituESEM Study

“…13−15 Furthermore, such a method has also been used to control the grain size distribution in the sintered material. 14 Vacuum or low environmental pressure sintering, therefore, provides an additional way of influencing the properties of sintered materials while being a method already implemented on a large scale in the industry (even though not yet on electrolytes). With the democratization of environmental SEM (ESEM) and the introduction of devices dedicated to performing in situ heating, samples can be observed directly during sintering and under various atmospheres, environmental pressures, and temperatures.…”