Determination of the effect of tungsten addition on the wear behavior of Fe-Al-Cr based iron aluminides

Iron (Fe)–Aluminum (Al) based materials have been studied for using under tough conditions like sea water, high temperature, high salty environment, under vacuum atmosphere, because of their perfect corrosion and oxidation resistance, lower cost, relatively high strength and wear resistance. Fe3Al (iron aluminide) intermetallic compound that are materials which have the potential to replace stainless steel in industrial applications because they have high strength/density ratio, lower cost, high wear resistance and high corrosion resistance under oxidation, sulfurization, carbonization environments at high temperatures. Unfortunately, there are limited studies about tribological properties of Fe3Al in water environments. In the study of project coordinator that is about high temperature behavior of chrome (Cr)–yttrium (Y) containing Fe–28Al (Fe3Al) intermetallic compound by tungsten addition, improvement of corrosion and strength values was obtained. In this study, wear behavior in dry and sea water environment of Fe–at.%28Al (Fe3Al) alloy, Fe–at.%28Al–5Cr alloys with tungsten addition at.% 0.5, 1.0, 1.5 and these quaternary alloys with at.% 0.1 Yttrium addition was investigated. Optical metallography (OM), X–ray diffraction analysis (XRD), scanning electron microscopy and energy dispersive x–ray spectroscopy (SEM/EDS) examinations were used to determine the material characterization and wear mechanism of the alloys produced by vacuum arc melting. The highest wear resistance was obtained in the Fe–Al–Cr alloy with 0.1 Y and 0.5 W content. In this alloy, effect of Y which is rare earth element that shows oxidation resistance is determined. In the seawater environment, Fe28Al alloy is exposed to both mechanical wear and chemical corrosion. The roughness and pits on the surface of Fe28Al and Fe28Al5Cr–W alloys indicate that abrasive wear occurs under the influence of mechanical forces such as friction and abrasion, and that salt and sand particles in seawater trigger this wear.